Invert If Action

[RblSb]

Some code duplication is started, so i moved some functions to another class. Let me know about other place/naming.
And i think this action looks pretty cool! (i hope inversion logic is good)

Demo cases:

class Main {
	static function main() {
		final obj = {flag: true};
		final arr = [0];
		var cb = (fn:()->Bool) -> false;
		while (false) {
			if (obj.flag) {
				trace("not last expr, ignore");
			}
			if (obj.flag) {
				trace(123);
			}
		}
		for (i in []) {
			trace(123);
			if (obj.flag && (obj.flag && arr[0] == 0 && cb(() -> obj.flag ? true : false)) && false) {
				trace(1);
				if (true) {
					trace(2);
				}
			}
		}
		do {
			if (obj.flag == true && !obj.flag == true) {
				trace(123);
			} else {
				trace("gen before return");
			}
		} while (false);

		if (true) {
			trace("not last expr, ignore");
		}

		if (obj.flag && (obj.flag == true) && obj.flag && arr[0] == 0) {
			trace(123);
		}
	}

	static function fooInt():Int {
		if (true) {
			trace(123);
		} else {
			trace("gen before return");
		}
		return (0 + 1);
	}

	static function fooInt2():Int {
		for (i in []) {
			if (false) {
				return 0;
			}
		}

		if (true) {
			trace(123);
			return 1;
		} else {
			trace("gen before return");
			return 0;
		}
	}

	static function fooException():Void {
		if (1 == 1) {
			trace(1);
			if (2 == 2) {
				trace(2);
			} else {
				trace("beforefoo2");
			}
		} else {
			trace("beforefoo");
		}
		throw "foo";
	}
}

[AlexHaxe]

can you add some basic unittests using your demo cases? (something like ExtractConstantFeatureTest)