queries in the case of a DAG, where a query reaches a node
visited earlier, but it's not on a cycle. This avoids
MayAlias results in cases where BasicAA is expected to
return MustAlias or PartialAlias in order to protect TBAA.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132609 91177308-0d34-0410-b5e6-96231b3b80d8
