Adding initial AsmParser implementation for the MBlaze backend. It is

Adding initial AsmParser implementation for the MBlaze backend. It is
mostly based on the ARM AsmParser at this time and is not particularly
functional.

Changed the MBlaze data layout from:
    "E-p:32:32-i8:8:8-i16:16:16-i64:32:32-f64:32:32-v64:32:32-v128:32:32-n32"
to:
    "E-p:32:32:32-i8:8:8-i16:16:16"
because the MicroBlaze doesn't have i64, f64, v64, or v128 data types.

Cleaned up the MBlaze source code:
    1. The floating point register class has been removed. The
       MicroBlaze does not have floating point registers. Floating
       point values are simply stored in integer registers.
    2. Renaming the CPURegs register class to GPR to reflect the
       standard naming.
    3. Removing a lot of stale code from AsmPrinter after
       the conversion to InstPrinter.
    4. Simplified sign extended loads by marking them as
       expanded in ISelLowering.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117054 91177308-0d34-0410-b5e6-96231b3b80d8