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

[Jonas Devlieghere via llvm-commits]

JDevlieghere wrote:

> Note a side effect in lldb-server [#132274 (comment)](https://github.com/llvm/llvm-project/pull/132274#issuecomment-2778431560) I recently reduced the size of lldb-server (Linux AArch64) from 47MB to 17MB and was going to reduce it to 8MB. But now it is impossible. Any suggestions?

The dump methods should only exist in assert builds. Do you ship lldb-server with assert enabled?

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