llvm-project

c1468e9c - [Clang] Don't give up on an unsuccessful function instantiation (#126723)

[Clang] Don't give up on an unsuccessful function instantiation (#126723) For constexpr function templates, we immediately instantiate them upon reference. However, if the function isn't defined at the time of instantiation, even though it might be defined later, the instantiation would forever fail. This patch corrects the behavior by popping up failed instantiations through PendingInstantiations, so that we are able to instantiate them again in the future (e.g. at the end of TU.) Fixes https://github.com/llvm/llvm-project/issues/125747