Subtracts an unsigned offset in bytes from a pointer.
`count` is in units of bytes.
This is purely a convenience for casting to a `u8` pointer and using [`sub`] on
it. See that method for documentation and safety requirements.
For non-`Sized` pointees this operation changes only the data pointer, leaving
the metadata untouched.
# Original
- [`<*T>::byte_sub`][orig]
- [`NonNull::byte_sub`]
# Similar Functions
- [`Pointer::byte_sub`]
- [`NonNullPointer::byte_sub`]
# Safety
See [`sub`].
[orig]: https://doc.rust-lang.org/std/primitive.pointer.html#method.byte_sub
[`sub`]: Self::sub