[clang] [clang][ASTImporter] Fix import of template parameter default values. (PR #100100)

[Donát Nagy via cfe-commits]

https://github.com/NagyDonat approved this pull request.

LGTM, I'm very grateful that you can understand and resolve these tricky `ASTImporter` issues.

https://github.com/llvm/llvm-project/pull/100100