[clang] [clang-tools-extra] [Clang] Unify interface for accessing template arguments as written for class/variable template specializations (PR #81642)

[Adrian Prantl via cfe-commits]

adrian-prantl wrote:

This broke several tests in the LLDB testsuite, I'm going to have to revert this.
https://green.lab.llvm.org/job/llvm.org/view/LLDB/job/as-lldb-cmake/3480/

https://github.com/llvm/llvm-project/pull/81642