[clang] [clang][Index][USR] Generate USRs for class-type non-type template arguments (PR #212356)

[Patryk Stefanski via cfe-commits]

patrykstefanski wrote:

> Maybe the best course of action would be picking this to swiftlang/stable/23.x

Yes, that's correct, I was planning to cherry-pick this to swiftlang/stable/23.x, since we need to fix the issue downstream.

https://github.com/llvm/llvm-project/pull/212356