[X86] Add a non-ambiguous check prefix to lwp-intrinsics.ll for the case when...

[X86] Add a non-ambiguous check prefix to lwp-intrinsics.ll for the case when only the feature is specified and not the CPUs.

Not sure why the script doesn't notice this. We just weren't checking the +lwp command in 32-bit mode in 2 of the test cases.

llvm-svn: 360282