[DAG][AArch64] Disable post-legalization store

Disable post-legalization store for AArch64 backend which is causing
errors out-of-tree.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@319607 91177308-0d34-0410-b5e6-96231b3b80d8
6 files changed