[llvm] [Bitcode] Add SkipDebugIntrinsicUpgrade hook to ParserCallbacks (PR #201456)

[Jeremy Morse via llvm-commits]

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

The code LGTM; I feel the wording on the `SkipDebugIntrinsicUpgrade` documentation should be strengthen to discourage anyone else from using it. The risk is that it's seen as a general escape hatch from new-debug-records and people spend time expecting the intrinsics to work, then are upset. Something perhaps like: "This flag allows direct manipulation of the old intrinsic-form, beware that LLVM does not support using these intrinsics any more".

https://github.com/llvm/llvm-project/pull/201456