[llvm] [llvm-debuginfo-analyzer] Use `LLVM_BUILD_DEBUG` in class definitions (PR #140265)

[Javier Lopez-Gomez via llvm-commits]

jalopezg-git wrote:

> I think we already have a separate macro for this - ABI_BREAKING_CHECKS, perhaps?

Hmmm... unsure; according to [llvm/docs/ProgrammersManual.rst](https://github.com/llvm/llvm-project/blob/main/llvm/docs/ProgrammersManual.rst), this PP macro serves a slightly different purpose, but we could probably also use it here.  WDYT, @CarlosAlbertoEnciso?

https://github.com/llvm/llvm-project/pull/140265