[PowerPC] Fix problems with large code model (PR17169).
Large code model on PPC64 requires creating and referencing TOC entries when
using the addis/ld form of addressing. This was not being done in all cases.
The changes in this patch to PPCAsmPrinter::EmitInstruction() fix this. Two
test cases are also modified to reflect this requirement.
Fast-isel was not creating correct code for loading floating-point constants
using large code model. This also requires the addis/ld form of addressing.
Previously we were using the addis/lfd shortcut which is only applicable to
medium code model. One test case is modified to reflect this requirement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190882
91177308-0d34-0410-b5e6-
96231b3b80d8