move an optimization for memcmp out of simplifylibcalls and into 
SDISel.  This optimization was causing simplifylibcalls to 
introduce type-unsafe nastiness.  This is the first step, I'll be 
expanding the memcmp optimizations shortly, covering things that
we really really wouldn't want simplifylibcalls to do.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92098 91177308-0d34-0410-b5e6-96231b3b80d8
5 files changed