[mips][msa] Added support for matching ffint_[us].[wd], and ftrunc_[us].[wd] from normal IR (i.e. not intrinsics)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@192429 91177308-0d34-0410-b5e6-96231b3b80d8