Revert "Remove various use of undef in the X86 test suite as patern involving undef can collapse them. NFC"

This reverts commit f0e85c194ae5e87476bc767304470dec85b6774f.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@333953 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed