[mips][msa] Direct Object Emission for I5 instructions.

This patch adds Direct Object Emission support for I5 instructions: addvi.{b,h,w,d}, ceqi.{b,h,w,d}, clei_s.{b,h,w,d}, clei_u.{b,h,w,d}, clti_s.{b,h,w,d}, clti_u.{b,h,w,d}, maxi_s.{b,h,w,d}, maxi_u.{b,h,w,d}, mini_s.{b,h,w,d}, mini_u.{b,h,w,d}, subvi.{b,h,w,d}.


Patch by Matheus Almeida

llvm-svn: 191687