Function get_prototype_if_ordinary 

pub(crate) unsafe extern "C" fn get_prototype_if_ordinary(
    _: *mut JSContext,
    proxy: HandleObject,
    is_ordinary: *mut bool,
    proto: MutableHandleObject,
) -> bool

If proxy (underneath any functionally-transparent wrapper proxies) has as its [[GetPrototypeOf]] trap the ordinary [[GetPrototypeOf]] behavior defined for ordinary objects, set *is_ordinary to true and store obj’s prototype in proto. Otherwise set *isOrdinary to false. In case of error, both outparams have unspecified value.

This implementation always handles the case of the ordinary [[GetPrototypeOf]] behavior. An alternative implementation will be necessary for maybe-cross-origin objects.

Safety

is_ordinary must point to a valid, non-null bool.