[llvm] [Analysis] Track offsets in PtrUseVisitor to revisit when required (PR #179726)

[Jameson Nash via llvm-commits]

vtjnash wrote:

Alright, I reimplemented using the more optimal version of this with just one path dictionary, instead of needing one for every entry. There's also another optimization I could make to stop storing APInt (it is required for doing the math with the correct bit-width truncation, to handle negative wrap-around, but not needed for storage which can be simply uint64), but only if that is actually useful.

https://github.com/llvm/llvm-project/pull/179726