Int can be re-assigned when returned from extern inline function

[Aurel300]

extern class Foobar {
	static var a:Int;
	static inline function foo():Int return a;
}
class Test {
	public static function main():Void {
		Foobar.foo() = 2;
	}
}

This should fail to compile with Test.hx:7: characters 3-15 : Invalid assign, but it does not. This could cause a runtime exception instead, e.g. on Python:

var a = Date.now();
a.getFullYear() = 3;

(Throws AttributeError: attribute 'year' of 'datetime.date' objects is not writable.)

[nadako]

Ouch. That's actually pretty bad, because my converter can currently generate code like a.getFullYear() = 3 in some cases, and my plan is/was to catch these cases by looking at Haxe compile errors :)