[Bug c/78284] warn on malloc with very large arguments

[msebor at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78284
Bug 78284 depends on bug 78668, which changed state.

Bug 78668 Summary: aligned_alloc, realloc, et al. missing attribute alloc_size
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78668

           What    |Removed                     |Added
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             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED