[libTooling] Add smart pointer support to the `access` Stencil

This extends smart pointer support beyond the existing `maybeDeref` and
`maybeAddressOf`.

Differential Revision: https://reviews.llvm.org/D100450

GitOrigin-RevId: 1c5717225e89d4b266784f1a1fe482530bc4b6f2
2 files changed