Tweak 3 tests in llvm/test/CodeGen/X86 to add -mcpu=generic since r195383.

They failed on bdver2 buildslave.

FIXME: FileCheck-ize them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@195407 91177308-0d34-0410-b5e6-96231b3b80d8