[mips][FastISel] Implement shift ops for Mips fast-isel.

Summary:
Add shift operators implementation to fast-isel for Mips.  These are shift ops
for non legal forms, i.e. i8 and i16.

Based on a patch by Reed Kotler.

Test Plan:

Reviewers: dsanders

Subscribers: echristo, rfuhler, llvm-commits

Differential Revision: http://reviews.llvm.org/D6726

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@235194 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed