[clang] [Sema] Fix crash on invalid operator template-id (PR #181404)

[Yanzuo Liu via cfe-commits]

zwuis wrote:

Please add a release note entry to "clang/docs/ReleaseNotes.rst", and reference the issue fixed by this PR. Thanks!

Otherwise LGTM, but please wait at least one weak to wait for other reviewers.

https://github.com/llvm/llvm-project/pull/181404