[llvm] [LLVM][Clang][AArch64] Implement AArch64 build attributes (PR #123990)

[Hans Wennborg via llvm-commits]

zmodem wrote:

Then it seems like this change breaks users of GNU ld who care about binary size?

Perhaps we should revert this until a proper fix is found.

https://github.com/llvm/llvm-project/pull/123990