[clang] [clang][ASTImporter] New fix for default template parameter values. (PR #101836)

[Donát Nagy via cfe-commits]

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

Feel free to merge this if you're not planning more changes.

The commit seems to be reasonable, I like that your comments explain the logic behind this very technical logic. I don't understand enough to recognize an unhandled corner case (if there was one), but I'm confident that this change is a good step forward.

https://github.com/llvm/llvm-project/pull/101836