pointer_structural_match lint will become a hard error soon

[RalfJung]

This crate triggers the pointer_structural_match lint:

ctti/src/impls.rs

Line 473 in 1ae5fa0

target: SELFREF_FN,

Matching against function pointers is not reliable and will become a hard error once rust-lang/rust#124661 lands, as was decided in rust-lang/rfcs#3535. I recommend comparing with == instead (though that will be just as unreliable).