AVX-512: insert element to mask vector; store i1 data

Implemented INSERT_VECTOR_ELT operation for v16i1 and v8i1 vectors;
Implemented "store" for i1 type


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205850 91177308-0d34-0410-b5e6-96231b3b80d8