search for: rl278220

I'm looking at the bug (https://llvm.org/bugs/show_bug.cgi?id=31181) which was triggered by my change to make CVP mark adds as no wrap (https://reviews.llvm.org/rL278220) and I'd like to have some broader discussion of the problem. In this bug CVP correctly marks an add as nuw basing on the loop latch check, but later loop rotation pass moves the add to a point before the check. In the new context nuw is no longer valid and leads to an incorrect transformation...