[MIPS][microMIPS] Fix PseudoMTLOHI_MM matching and expansion

On micromips MipsMTLOHI is always matched to PseudoMTLOHI_DSP regardless
of +dsp argument. This patch checks is HasDSP predicate is present for
PseudoMTLOHI_DSP so PseudoMTLOHI_MM can be matched when appropriate.

Add expansion of PseudoMTLOHI_MM instruction into a mtlo/mthi pair.

Patch by Mirko Brkusanin.

Differential Revision: http://reviews.llvm.org/D59203

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@356039 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed