[clang] [clang-tools-extra] [lldb] [clang] Reland: fix getTemplateInstantiationArgs (PR #208285)

[Shafik Yaghmour via cfe-commits]

shafik wrote:

I really appreciate everyone on this thread trying to make this happen, it is a lot of work and hopefully in a few more days we will have some more reproducers. 

https://github.com/llvm/llvm-project/pull/208285