[clang] [clang-tools-extra] [lldb] [clang] Reland: fix getTemplateInstantiationArgs (PR #207825)

[Shafik Yaghmour via cfe-commits]

https://github.com/shafik commented:

What is the main difference between this and the previous version you previously landed?

https://github.com/llvm/llvm-project/pull/207825