[mips] Guard traps for microMIPS correctly

This is part of fixing the instruction predicates for MIPS.

Reviewers: atanasyan, abeserminji

Differential Revision: https://reviews.llvm.org/D44212


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@327409 91177308-0d34-0410-b5e6-96231b3b80d8
17 files changed