[X86] Add test cases for failures to use narrow test with immediate...

[X86] Add test cases for failures to use narrow test with immediate instructions when a truncate is beteen the CMP and the AND and the sign flag is used.

The code in X86ISelDAGToDAG only looks through truncates if the sign flag isn't used, but that is overly restrictive. A future patch will improve this.

llvm-svn: 343355