Re-enable "[SCEV] Make isLoopEntryGuardedByCond a bit smarter"

The failures happened because of assert which was overconfident about
SCEV's proving capabilities and is generally not valid.

Differential Revision: https://reviews.llvm.org/D42835


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@324473 91177308-0d34-0410-b5e6-96231b3b80d8
7 files changed