[llvm] r305938 - [BasicAA] Use MayAlias instead of PartialAlias for fallback.

Hi Michael,

thank you for up-streaming this so quickly & Hal for reviewing this
fast.

@Roman: This helps to enable you pattern matching even after inlining.

Best,
Tobias

I think it's great. Thanks! I hope it'll be useful not only for our
pattern matching.