[AVX512] Extended avx512_binop_rm for AVX512VL subsets.
Added avx512_binop_rm_vl multiclass for VL subset
Added encoding tests



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219390 91177308-0d34-0410-b5e6-96231b3b80d8