[clang] [Clang][Concepts] Fix a constraint comparison regression for out-of-line ClassTemplateDecls (PR #102587)

[Younan Zhang via cfe-commits]

zyn0217 wrote:

@jcsxky Thanks for spotting that. That is indeed a regression and I think that can be resolved by not letting out-of-line specializations contribute to template arguments.

https://github.com/llvm/llvm-project/pull/102587