[clang] Diagnose misuse of the cleanup attribute (PR #80040)

[Bhuminjay Soni via cfe-commits]

11happy wrote:

> extern void free(void *);

Sure I already wrote some tests and will commit after locally checking them  but idk everytime I restart pc clang rebuilds itself and that is taking time, is it normal for clang to rebuild everytime I restart? (I think it has something to do with the dual boot setup linux/windows.)

https://github.com/llvm/llvm-project/pull/80040