[llvm] [RemoveDIs] Read/write DbgRecords directly from/to bitcode (PR #83251)

[Orlando Cazalet-Hyams via llvm-commits]

OCHyams wrote:

Squashed and formatted. I'll rebase then merge this (note that this now lands disabled by default so that we can have a more easily revertible capstone patch which just changes the default -- I'll follow up with that patch shortly). Thanks all!

https://github.com/llvm/llvm-project/pull/83251