[clang] [clang][Sema] Subclass `-Wshorten-64-to-32` under `-Wimplicit-int-conversion` (PR #80814)

[Aaron Ballman via cfe-commits]

https://github.com/AaronBallman commented:

LGTM aside from a minor change to the release notes, thank you for this improvement!

https://github.com/llvm/llvm-project/pull/80814