`ptr_eq` was recently enhanced to lint on more cases of raw pointers
comparison:
- lint on all raw pointer comparison, by proposing to use
`[core|std]::ptr::eq(lhs, rhs)` instead of `lhs == rhs`;
- removing one symetric `as usize` on each size if needed
- peeling any level of `as *[const|mut] _` if the remaining expression
can still be coerced into the original one (i.e., is a ref or raw
pointer to the same type as before)
The current change restricts the lint to the cases where at least one
level of symetric `as usize`, or any conversion to a raw pointer, could
be removed. For example, a direct comparaison of two raw pointers will
not trigger the lint anymore.
