Fixing -Wsign-compare warnings; NFC.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224337 91177308-0d34-0410-b5e6-96231b3b80d8
[mips][microMIPS] Implement SWP and LWP instructions
Differential Revision: http://reviews.llvm.org/D5667


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224338 91177308-0d34-0410-b5e6-96231b3b80d8