cases. See the comment above OptimizeSMax for the full story, and
the testcase for an example. This cancels out a pessimization
commonly attributed to indvars, and will allow us to lift some of
the artificial throttles in indvars, rather than add new ones.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56230 91177308-0d34-0410-b5e6-96231b3b80d8
