[clang] [clang] fix crash on qualified friend function definitions (PR #186398)

[via cfe-commits]

Serosh-commits wrote:

> LGTM, but please also fix the PR description, as it doesn't reflect the patch anymore.
> That's what will be used as the commit message.

Thanks yeah no problem I will update the old pr description to new one 

https://github.com/llvm/llvm-project/pull/186398