rdar://12329730 (defect 2)

Enhancement to InstCombine. Try to catch this opportunity:

 ---------------------------------------------------------------
 ((X^C1) >> C2) ^ C3  => (X>>C2) ^ ((C1>>C2)^C3)
  where the subexpression "X ^ C1" has more than one uses, and
  "(X^C1) >> C2" has single use.
 ----------------------------------------------------------------

 Reviewed by Nadav (with minor change per his request).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168615 91177308-0d34-0410-b5e6-96231b3b80d8

Remove unneeded #includes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168608 91177308-0d34-0410-b5e6-96231b3b80d8

Fix a comment bug in toascii simplifier

When I migrated the toascii simplifier in r168580 Benjamin Kramer noticed
a bug in one of the comments that I migrated.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168605 91177308-0d34-0410-b5e6-96231b3b80d8

instcombine: Migrate printf optimizations

This patch migrates the printf optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168604 91177308-0d34-0410-b5e6-96231b3b80d8

Move the code that uses SCEVs prior to creating the new loops.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168601 91177308-0d34-0410-b5e6-96231b3b80d8

Normalize splat 256bit vectors with 8 elements.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168600 91177308-0d34-0410-b5e6-96231b3b80d8

Decouple MCInstBuilder from the streamer per Eli's request.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168597 91177308-0d34-0410-b5e6-96231b3b80d8

Remove stray trailing backslash

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168592 91177308-0d34-0410-b5e6-96231b3b80d8

tsan: fix lint warnings

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168590 91177308-0d34-0410-b5e6-96231b3b80d8

Rewrite test to not use a FileCheck variable and redefine it on the same line.

In preparation for the FileCheck functionality change which will allow using
a variable later on the same line.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168588 91177308-0d34-0410-b5e6-96231b3b80d8

Add MCInstBuilder, a utility class to simplify MCInst creation similar to MachineInstrBuilder.

Simplify some repetitive code with it. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168587 91177308-0d34-0410-b5e6-96231b3b80d8

[tsan] add fail order to compare_exchange

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168586 91177308-0d34-0410-b5e6-96231b3b80d8

Fix a PassManager pointer use-after-free bug.
The bug can be triggered when we require LoopInfo analysis ahead of DominatorTree construction in a Module Pass. The cause is that the LoopInfo analysis itself also invokes DominatorTree construction, therefore, when PassManager schedules LoopInfo, it will add DominatorTree first. Then after that, when the PassManger turns to schedule DominatorTree invoked by the above ModulePass, it finds there is already a DominatorTree, so it delete the redundant one. However, somehow it still try to access that pass pointer after free as code pasted below, which results in segment fault.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168581 91177308-0d34-0410-b5e6-96231b3b80d8

instcombine: Migrate toascii optimizations

This patch migrates the toascii optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168580 91177308-0d34-0410-b5e6-96231b3b80d8

instcombine: Migrate isascii optimizations

This patch migrates the isascii optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168579 91177308-0d34-0410-b5e6-96231b3b80d8

instcombine: Migrate isdigit optimizations

This patch migrates the isdigit optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168578 91177308-0d34-0410-b5e6-96231b3b80d8

Removing SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG

Adding CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG
       C_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG

This is to handle the wackiness on a Mac host where cmake detects:

CMAKE_CXX_COMPILER == "/usr/bin/c++"
CMAKE_C_COMPILER == "/usr/bin/gcc"

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168577 91177308-0d34-0410-b5e6-96231b3b80d8

Fix gcc's -Wunused-but-set-variable warnings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168576 91177308-0d34-0410-b5e6-96231b3b80d8

Fix bogus comment;  no functional change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168575 91177308-0d34-0410-b5e6-96231b3b80d8

instcombine: Migrate *abs optimizations

This patch migrates the *abs optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168574 91177308-0d34-0410-b5e6-96231b3b80d8

instcombine: Migrate ffs* optimizations

This patch migrates the ffs* optimizations from the simplify-libcalls
pass into the instcombine library call simplifier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168571 91177308-0d34-0410-b5e6-96231b3b80d8

Move the max vector width to a constant parameter. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168570 91177308-0d34-0410-b5e6-96231b3b80d8

Fix the document style.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168569 91177308-0d34-0410-b5e6-96231b3b80d8

Refactor the ptr runtime check generation code. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168568 91177308-0d34-0410-b5e6-96231b3b80d8

Code Custodian:
  - Widespread trailing space removal
  - A dash of OCD spacing to block align enums
  - joined a line that probably needed 80 cols a while back

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168566 91177308-0d34-0410-b5e6-96231b3b80d8

Add support for .cfi_register now that it is easy to extent the representation
to support it. Original patch with the parsing and plumbing by the PaX team and
Roman Divacky. I added the bits in MCDwarf.cpp and the test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168565 91177308-0d34-0410-b5e6-96231b3b80d8

Move semantics are great, don't destroy the optimization opportunity with trivial copy ctors.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168561 91177308-0d34-0410-b5e6-96231b3b80d8

Rename method. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168560 91177308-0d34-0410-b5e6-96231b3b80d8

The induction-pointer work is inspired by a research paper. This commit adds a reference.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168559 91177308-0d34-0410-b5e6-96231b3b80d8

Add support for pointer induction variables even when there is no integer induction variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168558 91177308-0d34-0410-b5e6-96231b3b80d8

Refactor to make helper method static.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168557 91177308-0d34-0410-b5e6-96231b3b80d8

Further cleanups. Thanks for Sean Silva for noticing it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168556 91177308-0d34-0410-b5e6-96231b3b80d8

Add an extra slash so doxygen comments will be properly recognized.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168554 91177308-0d34-0410-b5e6-96231b3b80d8

Remove duplicate check of LimitFloatPrecision. It was already checked earlier before IsExp10 could be set to true.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168553 91177308-0d34-0410-b5e6-96231b3b80d8

Factor common code out of individual if blocks into common tail.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168551 91177308-0d34-0410-b5e6-96231b3b80d8

Remove redundant calls to getCurDebugLoc in visitIntrinsicCall. It's already called at the start of the function and captured in a local variable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168548 91177308-0d34-0410-b5e6-96231b3b80d8

Refactor a bit to make some helper methods static.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168546 91177308-0d34-0410-b5e6-96231b3b80d8

libLTO: Add a utility method to initialize the disassemblers.

Necessary to give disassembler users (like darwin's otool) a possibility to
dlopen libLTO and still initialize the required LLVM bits. This used to go
through libMCDisassembler but that's a gross layering violation, the MC layer
can't pull in functions from the targets. Adding a function to libLTO is a bit
of a hack but not worse than exposing other disassembler bits from libLTO.

Fixes PR14362.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168545 91177308-0d34-0410-b5e6-96231b3b80d8

PPC: Reinstate the fatal error when trying to emit a macho file.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168543 91177308-0d34-0410-b5e6-96231b3b80d8

ARM: Share applyFixup between ELF and Darwin.

The implementations already diverged a bit, merge them back together.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168542 91177308-0d34-0410-b5e6-96231b3b80d8

PPC: MCize most of the darwin PIC emission.

The last remaining bit is "bcl 20, 31, AnonSymbol", which I couldn't find the
instruction definition for. Only whitespace changes in assembly output.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168541 91177308-0d34-0410-b5e6-96231b3b80d8

PPC: Share applyFixup between ELF and Darwin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168540 91177308-0d34-0410-b5e6-96231b3b80d8

PPC: Simplify code with Twines.

No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168539 91177308-0d34-0410-b5e6-96231b3b80d8

Factor some common code out of individual if blocks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168538 91177308-0d34-0410-b5e6-96231b3b80d8

Change the representation of MCCFIInstruction.

We now store the Register and Offset directly. MachineLocation is gone (from
this file)!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168536 91177308-0d34-0410-b5e6-96231b3b80d8

Give each MCCFIInstruction its own opcode.
This untangles the switch cases of the old Move and RelMove opcodes a bit
and makes it clear how to add new instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168534 91177308-0d34-0410-b5e6-96231b3b80d8

Move a bit of duplicated code into a helper function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168533 91177308-0d34-0410-b5e6-96231b3b80d8

Refactor how MCCFIInstructions are created.

Give MCCFIInstruction a single, private constructor and add helper static
methods that create each type of cfi instruction. This is is preparation
for changing its representation. The representation with a pair
MachineLocations older than MC and has been abused quiet a bit to support
more cfi instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168532 91177308-0d34-0410-b5e6-96231b3b80d8

CodeGenPrepare: Move ret duplication out of the instruction iteration loop.

It can delete the block, and the loop continues on free'd memory.
No change in output. Found by valgrind.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168525 91177308-0d34-0410-b5e6-96231b3b80d8

Refactor a bit to make some helper functions static.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168524 91177308-0d34-0410-b5e6-96231b3b80d8

Add a -disable-cfi option to llvm-mc. This is useful for debugging as
it will expand any .cfi_* directives in the input assembly.

Unfortunately this cannot replace elf-dump in tests as the asm streamer
cannot relax the line advance opcodes.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168522 91177308-0d34-0410-b5e6-96231b3b80d8

Implement .cfi_undefined. Based on a patch from PaX team, updated by
Roman Divacky. I just added the testcase.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168520 91177308-0d34-0410-b5e6-96231b3b80d8

Disallow the undocumented practice of starting the datalayout string with '-'.

Update some test cases accordingly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168516 91177308-0d34-0410-b5e6-96231b3b80d8

Update call to the new syntax.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168512 91177308-0d34-0410-b5e6-96231b3b80d8

Remove unused parameter Penalty from the BoundsChecking pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168511 91177308-0d34-0410-b5e6-96231b3b80d8

Cleanup: Simplify loop end logic in computeRegisterProperties().

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168507 91177308-0d34-0410-b5e6-96231b3b80d8

Added me as the owner of the Sparc backend

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168504 91177308-0d34-0410-b5e6-96231b3b80d8

Mark me as the owner of the gold plugin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168502 91177308-0d34-0410-b5e6-96231b3b80d8

Add more functions to the target library information.

I discovered a few more missing functions while migrating optimizations
from the simplify-libcalls pass to the instcombine (I already added some
in r167659).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168501 91177308-0d34-0410-b5e6-96231b3b80d8

llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp: Prune AddressSanitizerCreateGlobalRedzonesPass::ID. [-Wunused-variable]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168499 91177308-0d34-0410-b5e6-96231b3b80d8

Fix 80-col violation

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168498 91177308-0d34-0410-b5e6-96231b3b80d8

IntelJITEventsWrapper.h: Prune two members, FinalizeThreadFunc and FinalizeProcessFunc, for now. [-Wunused-private-field]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168495 91177308-0d34-0410-b5e6-96231b3b80d8

Documentation: convert SourceLevelDebugging.html to reST

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168493 91177308-0d34-0410-b5e6-96231b3b80d8

Remove 'sretpromotion' pass from the documentation. This pass is long
dead.

Patch by Stephan Falke.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168492 91177308-0d34-0410-b5e6-96231b3b80d8

Generalize matching of add_executable to add_XXX_executable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168490 91177308-0d34-0410-b5e6-96231b3b80d8

llvm.fmuladd.* lowering should be checking isOperationLegalOrCustom, rather than
isOperationLegal. Thanks to Craig Topper for pointing this out.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168485 91177308-0d34-0410-b5e6-96231b3b80d8

[asan] rip off the creation of global redzones from the main AddressSanitizer class into a separate class. The intent is to make it a separate ModulePass in the following commmits

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168484 91177308-0d34-0410-b5e6-96231b3b80d8

Pull some code out into functions to make rearranging them a bit easier.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168481 91177308-0d34-0410-b5e6-96231b3b80d8

Corrects a problem where we reply exclusively of GEPs to drive
analysis.  Better is to look for cases with useful GEPs and use them
when possible.  When a pair of useful GEPs is not available, use the
raw SCEVs directly. This approach supports better analysis of pointer
dereferencing.

In parallel, all the test cases are updated appropriately.
Cases where we have a store to *B++ can now be analyzed!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168474 91177308-0d34-0410-b5e6-96231b3b80d8

Mips direct object xgot support

This patch provides support for the MIPS relocations:

    *)  R_MIPS_GOT_HI16
    *)  R_MIPS_GOT_LO16
    *)  R_MIPS_CALL_HI16
    *)  R_MIPS_CALL_LO16

These are used for large GOT instruction sequences.

Contributer: Jack Carter

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168471 91177308-0d34-0410-b5e6-96231b3b80d8

Fix a typo in FileCheck.rst

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168466 91177308-0d34-0410-b5e6-96231b3b80d8

[mips] Generate big GOT code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168460 91177308-0d34-0410-b5e6-96231b3b80d8

Adding tests for the Intel JIT event listener's MCJIT support.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168459 91177308-0d34-0410-b5e6-96231b3b80d8

[mips] Simplify lowering functions in MipsISelLowering.cpp by using the helper
functions added in r168456.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168458 91177308-0d34-0410-b5e6-96231b3b80d8

[mips] Add helper functions that create nodes for computing address.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168456 91177308-0d34-0410-b5e6-96231b3b80d8

[mips] Add command line option "-mxgot".

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168455 91177308-0d34-0410-b5e6-96231b3b80d8

[mips] When a node which loads from a GOT is created, pass a MachinePointerInfo
referring to a GOT entry.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168453 91177308-0d34-0410-b5e6-96231b3b80d8

Add new predicates for the immediate operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168451 91177308-0d34-0410-b5e6-96231b3b80d8

[mips] Add target operand flag enums for big GOT relocations.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168450 91177308-0d34-0410-b5e6-96231b3b80d8

Use one common 'let' expression to set PrintMethod for all immediate operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168449 91177308-0d34-0410-b5e6-96231b3b80d8

Add relocations used for mips big GOT.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168448 91177308-0d34-0410-b5e6-96231b3b80d8

test commit: added a few comments

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168445 91177308-0d34-0410-b5e6-96231b3b80d8

Implementing basic function-level profiling support in IntelJITEventListener.

Tests to follow in another patch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168444 91177308-0d34-0410-b5e6-96231b3b80d8

Add support for varargs functions for msp430.
Patch by Job Noorman!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168440 91177308-0d34-0410-b5e6-96231b3b80d8

Add support for byval args. Patch by Job Noorman!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168439 91177308-0d34-0410-b5e6-96231b3b80d8

Finish the renaming.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168437 91177308-0d34-0410-b5e6-96231b3b80d8

Renamed HexagonImmediates.td -> HexagonOperands.td.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168434 91177308-0d34-0410-b5e6-96231b3b80d8

llvm/test/Transforms/InstCombine/sdiv-1.ll: FileCheck-ize.

"not grep '-715827882'" performed as below...bad...

Usage: grep [OPTION]... PATTERN [FILE]...
Try `grep --help' for more information.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168430 91177308-0d34-0410-b5e6-96231b3b80d8

Using "not grep" is brittle as the test passes if llvm-as fails.
Fix the testcase to be valid IL and uses FileCheck.
Thanks to NAKAMURA Takumi for noticing it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168427 91177308-0d34-0410-b5e6-96231b3b80d8

PR14055: Implement support for sub-vector operations in SROA.

Now if we can transform an alloca into a single vector value, but it has
subvector, non-element accesses, we form the appropriate shufflevectors
to allow SROA to proceed. This fixes PR14055 which pointed out a very
common pattern that SROA couldn't handle -- mixed vec3 and vec4
operations on a single alloca.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168418 91177308-0d34-0410-b5e6-96231b3b80d8

Fix execution domain for packed FMA4 instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168417 91177308-0d34-0410-b5e6-96231b3b80d8

Mark ISD::FMA as Legal instead of custom for x86 with FMA3/FMA4. Needed so that llvm.muladd can be converted to ISD::FMA for fp_contract.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168413 91177308-0d34-0410-b5e6-96231b3b80d8

Make calcLiveInMask method static.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168409 91177308-0d34-0410-b5e6-96231b3b80d8

Make isScratchReg and isFPCopy methods static.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168407 91177308-0d34-0410-b5e6-96231b3b80d8

Whitespace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168402 91177308-0d34-0410-b5e6-96231b3b80d8

Update for some of the coding standard before rearranging functions
around.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168401 91177308-0d34-0410-b5e6-96231b3b80d8

Update some comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168400 91177308-0d34-0410-b5e6-96231b3b80d8

Update and add some comments.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168399 91177308-0d34-0410-b5e6-96231b3b80d8

Whitespace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168398 91177308-0d34-0410-b5e6-96231b3b80d8

Add a tests for the new -no-show-raw-insn option of llvm-objdump.

This also initiates a test/tools directory where tools-specific tests can be
placed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168397 91177308-0d34-0410-b5e6-96231b3b80d8