Possible unsound safe API

[charlesxsh]

the prefetch is public accessible, and the offset does not have the appropriate check, which can cause user/developer might causing memory issue by merely using safe API.

halo2curves/src/lib.rs

Lines 33 to 40 in ee35b4e

	pub fn prefetch<T>(data: &[T], offset: usize) {
	use core::arch::x86_64::_mm_prefetch;
	unsafe {
	_mm_prefetch(
	data.as_ptr().add(offset) as *const i8,
	core::arch::x86_64::_MM_HINT_T0,
	);
	}

Suggestion:

1. notify rustsec for this issue
2. mark it as unsafe to notify developer that this function might have memory risks