SCEV: Use I = vector<>.erase(I) to iterate and delete at the same time

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208282 91177308-0d34-0410-b5e6-96231b3b80d8
AArch64/ARM64: Port NEON post-increment load/store with 2/3/4 vectors to ARM64 backend.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@208284 91177308-0d34-0410-b5e6-96231b3b80d8