Revert "[DAG] Rewrite areNonVolatileConsecutiveLoads to use BaseIndexOffset"

This reverts commit r306819 which appears be exposing underlying
issues in a stage1 ppc64be build

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@306820 91177308-0d34-0410-b5e6-96231b3b80d8
10 files changed