avm1: SWFv5 should coerce functions to 0 #6285
Description
trace(typeof Array); // function
trace(3 - Array); // 3 (NaN in Ruffle)
trace(Array - Array); // 0 (NaN in Ruffle)
function t() {}
trace(typeof t); // function
trace(3 - t); // 3 (NaN in Ruffle)
trace(t - t); // 0 (NaN in Ruffle)
// This behaviour doesn't apply to objects and movie clips.
var a = new Sound();
trace(typeof a); // object
trace(3 - a); // NaN
trace(typeof _root); // movieclip
trace(3 - _root); // NaN
In SWFv6 and the next versions, this behaviour no longer applies as NaN is returned, so everything is correct in Ruffle.
(see #6390 (comment) for how this should get implemented)