[clang] [llvm] [Clang] Emit DW_TAG_template_alias for template aliases (PR #87623)

[Orlando Cazalet-Hyams via cfe-commits]

OCHyams wrote:

> LLVM IR parts look good to me.

Thanks!

@pogo59 said:

> Converting frame-types.s from v4 to v5 should be done as a separate commit. Then adding the alias would be a simpler change to review.

I've split that into two commits in this PR: upgrade to v5: [18446f2](https://github.com/llvm/llvm-project/pull/87623/commits/18446f27e31803057d9d90c957e5e191eb263b7b), add template alias: [49d6642](https://github.com/llvm/llvm-project/pull/87623/commits/49d66423ae61baf9cacd42c2b57333e09e4c1e81). It does improve readability a bit but its still quite noisy. I am happy to commit the former separately then rebase this PR, if you'd like? 

https://github.com/llvm/llvm-project/pull/87623