llvm

04d20b17 - [concepts] Set up an instantiation scope for constraint expression comparison (#79698)

[concepts] Set up an instantiation scope for constraint expression comparison (#79698) This is a follow-up for the comparison of constraints on out-of-line function template definitions. We require the instantiation of a ParmVarDecl while transforming the expression if that Decl gets referenced by a DeclRefExpr. However, we're not actually performing the class or function template instantiation at the time of such comparison. Therefore, let's map these parameters to themselves so that they get preserved after the substitution. Fixes https://github.com/llvm/llvm-project/issues/74447.