[OperandBundles] Teach AliasAnalysis about operand bundles

Summary:
If a `CallSite` has operand bundles, then do not peek into the called
function to get a more precise `ModRef` answer.

This is tested using `argmemonly`, `-basicaa` and `-gvn`; but the
functionality is not specific to any of these.

Depends on D13961

Reviewers: reames, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13962

llvm-svn: 250974