[clang] [Clang] Fix an assertion in the resolution of perfect matches (PR #140073)

[Caslyn Tonelli via cfe-commits]

Caslyn wrote:

Hi @cor3ntin, 

Would you please revert this change while resolving this failure case? I've attached a reproducer for this assert scenario to help with debugging.

[command_line_options-df343c.zip](https://github.com/user-attachments/files/20257098/command_line_options-df343c.zip)


https://github.com/llvm/llvm-project/pull/140073