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

[Orlando Cazalet-Hyams via llvm-commits]

OCHyams wrote:

Thanks! And good idea, I've asked for additional opinions on discourse [here](https://discourse.llvm.org/t/considerations-when-adding-new-bitcode-records/77660).

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