[clang] [clang] Allow builtin addc/subc to be constant evaluated (PR #81656)

[Bryce Wilson via cfe-commits]

Bryce-MW wrote:

I swear I had meant to add tests! I did see a place that looks good to add them before so I've done that. Which allowed me to find out that I had not done my implementation correctly so I fixed that up.

https://github.com/llvm/llvm-project/pull/81656