[mips][microMIPS] Implement ABS.fmt, CEIL.L.fmt, CEIL.W.fmt, FLOOR.L.fmt, FLOOR.W...

[mips][microMIPS] Implement ABS.fmt, CEIL.L.fmt, CEIL.W.fmt, FLOOR.L.fmt, FLOOR.W.fmt, TRUNC.L.fmt, TRUNC.W.fmt, RSQRT.fmt and SQRT.fmt instructions
Differential Revision: http://reviews.llvm.org/D11674

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@246968 91177308-0d34-0410-b5e6-96231b3b80d8