[mips] Add microMIPSR6 ll/sc instructions.

Previously the compiler was using the microMIPSR3 variants, incorrectly.

Reviewers: atanasyan, abeserminji, smaksimovic

Differential Revision: https://reviews.llvm.org/D46948


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@332820 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed