Tweak my last commit to be less conservative about uses.

We still save an instruction when just the "and" part is replaced.
Also change the code to match comments more closely.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147753 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed