[libc-commits] [libc] [libc] fixup missing include for fullbuild (PR #87266)

[Nick Desaulniers via libc-commits]

nickdesaulniers wrote:

>       Which is: 18446744073709551585

That's 11 - 42 == (`WRITE_SIZE - offseto`) interpreted as a 64b int.

https://github.com/llvm/llvm-project/pull/87266