-Fix binary codes and rename operands in .td files so that automatically
generated function MipsCodeEmitter::getBinaryCodeForInstr gives correct
encoding for instructions.
-Define new class FMem for instructions that access memory.
-Define new class FFRGPR for instructions that move data between GPR and
FPU general and control registers.
-Define custom encoder methods for memory operands, and also for size
operands of ext and ins instructions.
-Only static relocation model is currently implemented.

Patch by Sasa Stankovic

llvm-svn: 142378