More information on this behavior in the link below.
> Note that, apart from contrived examples with deleted null checks, the current rules do not actually help the compiler meaningfully optimize code. A memcpy implementation cannot rely on pointer validity to speculatively read because, even though memcpy(NULL, NULL, 0) is undefined, slices at the end of a buffer are fine. [And if the end of the buffer] were at the end of a page with nothing allocated afterwards, a speculative read from memcpy would break
> Note that, apart from contrived examples with deleted null checks, the current rules do not actually help the compiler meaningfully optimize code. A memcpy implementation cannot rely on pointer validity to speculatively read because, even though memcpy(NULL, NULL, 0) is undefined, slices at the end of a buffer are fine. [And if the end of the buffer] were at the end of a page with nothing allocated afterwards, a speculative read from memcpy would break
https://davidben.net/2024/01/15/empty-slices.html