How do the literal 0 comparisons fit into the language? Are they special purpose syntax or is it possible to write your own operator that only typechecks if the RHS is a literal 0?
The values of these comparison categories can be compared against the literal 0 (not any int, not an int whose value is 0... just the literal) using any of the six comparison operators...
IIUC it's referring to how you can safely evaluate the return value from a spaceship: by comparing against literal zero. (not how you would overload a comparison with literal zero).
It is a bit worrying that such an overloaded meaning is added again to the language.