[x86] simplify test and tighten checks

I noticed this test as part of:
http://reviews.llvm.org/D11393
...which is confusing enough as-is. 
Let's show the exact codegen, so the changes will be more obvious.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262874 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed