[clang] [Clang] Make matrix type trivially copyable (PR #193634)

[Farzon Lotfi via cfe-commits]

farzonl wrote:

This pr looks to be in better shape. I'm trying to go through my previous review and I can't because comments were delete. Please don't do that going forward.
<img width="954" height="120" alt="image" src="https://github.com/user-attachments/assets/e5958469-1d81-4d5d-9d7e-07911696d34f" />


https://github.com/llvm/llvm-project/pull/193634