[llvm] [DebugInfo] Add an specification_of attribute to LLVM DebugInfo (PR #115362)

[Augusto Noronha via llvm-commits]

augusto2112 wrote:

I'm upstreaming this from the downstream `swiftlang/llvm-project` repo. This is used for Swift, but could also be used in C++ to describe templated types.

https://github.com/llvm/llvm-project/pull/115362