Revert "[SCEV] Enable SCEV verification by default in EXPENSIVE_CHECKS builds"

This reverts commit r301150.  It breaks CodeGen/Hexagon/hwloop-wrap2.ll, reverting
while I investigate.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@301154 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed