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

[Petr Hosek via cfe-commits]

petrhosek wrote:

> > @petrhosek : could you perhaps share a good way to reproduce that consistently? Our CI/buildbots don't seem to have caught it.
> 
> +1

Here are the reproducers from all the failing libc++ tests.

[assign_range-d06603.tar.gz](https://github.com/user-attachments/files/29878514/assign_range-d06603.tar.gz)
[assign_range-db8647.tar.gz](https://github.com/user-attachments/files/29878515/assign_range-db8647.tar.gz)
[construct_from_range-c7143a.tar.gz](https://github.com/user-attachments/files/29878516/construct_from_range-c7143a.tar.gz)
[insert_range-4dc971.tar.gz](https://github.com/user-attachments/files/29878517/insert_range-4dc971.tar.gz)
[insert_range-69b649.tar.gz](https://github.com/user-attachments/files/29878518/insert_range-69b649.tar.gz)



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