[X86][SSE] Add ashr + mask test cases.

Test cases showing cases where we're missing an opportunity to lshr a value with an extended sign to avoid loading a mask

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298716 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed