[clang] [clang] Bailout when the substitution of template parameter mapping is invalid. (PR #86869)

[Haojian Wu via cfe-commits]

hokein wrote:

> LGTM, interesting it looks like we don't do this check in fromContraintExpr either.

Yes, I think it is an oversight, we should do the check for it as well.

https://github.com/llvm/llvm-project/pull/86869