[clang] [lldb] [clang-tools-extra] [c++20] P1907R1: Support for generalized non-type template arguments of scalar type. (PR #78041)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

Ping @rjmccall for Itanium mangling expertise to make sure we're matching the spec.

There are a few merge conflicts that also cropped up which need to be resolved, but overall I think this is pretty close to ready to try to re-land. It would be nice if we could get this in before the Clang 18 branch next Tue if possible (no pressure though).

https://github.com/llvm/llvm-project/pull/78041