GDScript: Add support for variadic functions

modules/gdscript/tests/scripts/runtime/features/variadic_functions.gd

@@ -0,0 +1,38 @@
+class A:
+	func f(x: int) -> void:
+		print(x)
+
+class B extends A:
+	func f(x: int, ...args: Array) -> void:
+		prints(x, args)
+
+class C extends B:
+	func f(x: int, y: int = 0, ...args: Array) -> void:
+		prints(x, y, args)
+
+class D extends C:
+	func f(...args: Array) -> void:
+		print(args)
+
+func test_func(x: int, y: int = 0, ...args: Array) -> void:
+	prints(x, y, args)
+
+var test_lambda := func (x: int, y: int = 0, ...args: Array) -> void:
+	prints(x, y, args)
+
+func test():
+	for method in get_method_list():
+		if str(method.name).begins_with("test_"):
+			print(Utils.get_method_signature(method))
+
+	test_func(1)
+	test_func(1, 2)
+	test_func(1, 2, 3)
+	test_func(1, 2, 3, 4)
+	test_func(1, 2, 3, 4, 5)
+
+	test_lambda.call(1)
+	test_lambda.call(1, 2)
+	test_lambda.call(1, 2, 3)
+	test_lambda.call(1, 2, 3, 4)
+	test_lambda.call(1, 2, 3, 4, 5)