[Loop Vectorizer] Consecutive memory access - fixed and simplified

Amended consecutive memory access detection in Loop Vectorizer.
Load/Store were not handled properly without preceding GEP instruction.

Differential Revision: https://reviews.llvm.org/D20789



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281853 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed