[llvm] Add __attribute__((retain)) to LLVM_DUMP_METHOD (PR #133025)

[Matthias Braun via llvm-commits]

MatzeB wrote:

Are you disabling the dumpers already? The dump functions can be independently disabled via `cmake -DLLVM_ENABLE_DUMP=OFF`  (they should be off by default for release builds and on by the default for assertion-enabled builds). I assume you don't need those dumper functions when you create release packages for lldb?

(I guess it's possible some code in LLVM forgot to check for the `LLVM_ENABLE_DUMP` macro, but that should be considered a bug and should be easy to fix/submit patches for).

https://github.com/llvm/llvm-project/pull/133025