`reallyUnsafePtrEquality#` should be levity polymorphic
I don't see why we couldn't use reallyUnsafePtrEquality#
on types of kind UnliftedRep
. Currently, we have to throw in an additional unsafeCoerce
to achieve equality comparison of unlifted pointers.
This would allow to subsume sameMutableByteArray#
and the requested sameByteArray#
(#9192 (closed)) primitives. They are already lowered by the same Cmm MachOp
, which is MO_Eq
.