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

[Javier Lopez-Gomez via llvm-commits]

jalopezg-git wrote:

> That is something to guard with `LLVM_ENABLE_ABI_BREAKING_CHANGES` as that is changing the object layout itself between release and debug builds. However, the returning of the value between `0` and `ID` is something that can remain as `NDEBUG` only.

LGTM; with `LLVM_BUILD_DEBUG`, I tried to mimic the most probable original intent of `NDEBUG`, but in a way that doesn't break downstream projects.
Going for `LLVM_ENABLE_ABI_BREAKING_CHECKS` looks also good and I can change it now.  Do we have general consensus?

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