Follow-up fix to r165928: handle memset rewriting for widened integers,
and generally clean up the memset handling. It had rotted a bit as the
other rewriting logic got polished more.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165930 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed