[clang] [clang] CWG2398: improve overload resolution backwards compat (PR #107350)

[Matheus Izvekov via cfe-commits]

mizvekov wrote:

This implements the wording I presented here: https://lists.isocpp.org/core/2024/09/16266.php
This will be part of the next revision of P3310.

https://github.com/llvm/llvm-project/pull/107350