eq_op false positive with floats

Consider the following function:

fn nan_test() -> bool {
	let v = std::f32::NAN;

	v != v //warning: equal expressions as operands to `!=`
}

The eq_op warning is wrong here since floats only implement PartialOrd and doing v != v allows me to detect them in a generic context:

fn max<T: PartialOrd>(v1: T, v2: T) -> T {
	if v2 != v2 { v2 }
	else if v2 > v1 { v2 } else { v1 }
}

Maybe a solution is to check whether the result of the expression returns something that implements Ord or not?

Start with the eq_op lint and reproduce the warning using the provided nan_test and generic max examples. Investigate how operand types and PartialOrd versus Ord are identified; done means valid float NaN checks no longer trigger the false positive while ordinary equal-expression warnings remain covered by tests.