[clang] [serialization] no transitive decl change (PR #92083)

[via cfe-commits]

alexfh wrote:

To clarify a bit more: the host platform Clang runs on is x86-64 in all cases described here by myself, @joanahalili, @asmok-g, @bgra8 and @ilya-biryukov. What may be specific to aarch64 is a set of headers conditionally-included just when compiling for ARM platforms.

As @ilya-biryukov mentioned, I'm now gathering profiles from Clang performing the problematic compilation before and after this patch.

https://github.com/llvm/llvm-project/pull/92083