Confusing error message for deterministic equality check

[shicks]

repro

The following error message is a bit confusing:

/** @constructor */
function Foo() {}
/** @constructor */
function Bar() {}

function f(/** ?Foo */ foo, /** ?Bar */ bar) {
  if (foo === bar) throw '';
}

input0:7: WARNING - condition always evaluates to false
left : (Foo|null)
right: (Bar|null)
  if (foo === bar) throw '';
      ^^^^^^^^^^^

This is inaccurate - the condition does not always evaluate to false. It is suspicious code and probably not what the user intended, but to be completely accurate we should check if the two sides both include null/undefined and if that's the case then add a bit about "for non-trivial values", or say "instead check foo == null && bar == null" or something.