Reduction like is now a memory access property

- Remove the statement reduction like property
+ Add the reduction like property to memory accesses


git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@211372 91177308-0d34-0410-b5e6-96231b3b80d8
[Refactor] Simplify memory access isWrite


git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@211379 91177308-0d34-0410-b5e6-96231b3b80d8