This is a resubmittal. For some reason it broke the bots yesterday
but I cannot reproduce the problem and have scrubed my sources and
even tested with llvm-lit -v --vg.

The Mips RDHWR (Read Hardware Register) instruction was not 
tested for assembler or dissassembler consumption. This patch
adds that functionality.

Contributer: Vladimir Medic
 


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172685 91177308-0d34-0410-b5e6-96231b3b80d8