[X86][Codegen] adding masked gathers tests for avx2

related to patch: https://reviews.llvm.org/D35772
adding llvm gathers test before gathers codegen support.

Differential Revision: https://reviews.llvm.org/D37800



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@313516 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed