[LoopPred] Hoist and of predicated checks where legal

If we have multiple range checks which can be predicated, hoist the and of the results outside the loop.  This minorly cleans up the resulting IR, but the main motivation is as a building block for D60093.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358419 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed