[clang] (New) Add option to generate additional debug info for expression dereferencing pointer to pointers (PR #95298)

[Jeremy Morse via cfe-commits]

https://github.com/jmorse approved this pull request.

LGTM, thanks for rapidly rewriting this. I think dereferencing the insertion iterator with `&**` will eventually need addressing with the move away from intrinsics and insertion, but that can be a matter for when the DIBuilder APIs get deprecated / retired.

https://github.com/llvm/llvm-project/pull/95298