[clang] Fix for merging PR #89456 into llvm 18.X (PR #90118)

[Eli Friedman via cfe-commits]

efriedma-quic wrote:

We don't merge anything against the release branch until the buildbots pass.  For the buildbots to run, someone needs to manually create a pull request against 18.x branch containing both the original patch and whatever changes are necessary to make the buildbots pass.

https://github.com/llvm/llvm-project/pull/90118