[clang] [X86_64] fix arg pass error in struct. (PR #86902)

[Eli Friedman via cfe-commits]

efriedma-quic wrote:

Try rebasing your patch?  If you're unlucky, you might have based your patch on a bad revision of main (and the buildbot just uses your branch as-is).

https://github.com/llvm/llvm-project/pull/86902