[AA] Refine ModRefInfo for llvm.memcpy.* in presence of operand bundles

[AA] Refine ModRefInfo for llvm.memcpy.* in presence of operand bundles

Presence of operand bundles changes semantics in respect to ModRef. In particular, spec says: "From the compilers perspective, deoptimization operand bundles make the call sites theyre attached to at least readonly. They read through all of their pointer typed operands (even if theyre not otherwise escaped) and the entire visible heap. Deoptimization operand bundles do not capture their operands except during deoptimization, in which case control will not be returned to the compiled frame". Fix handling of llvm.memcpy.* according to the spec.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D118033