Improve ClassDB::_is_parent_class performance

[aaronp64]

Change ClassDB::_is_parent_class to use ClassInfo::inherits_ptr, instead of looking up each inherited class name.

This speeds up Array type checking - adding to a typed Array can be around 2x faster, depending on how many inherited classes are between the object being added and the Array's type. Also speeds up casting/type checking in gdscript with as/is for native types.

Comparison gdscript below:

func _ready() -> void:
	test_untyped_array()
	test_node_button_array()
	test_node_node3d_array()
	test_cast()

func test_untyped_array():
	var a : Array = []
	var start_time = Time.get_ticks_msec()
	for i in 1000000:
		a.push_back(i)
	var end_time = Time.get_ticks_msec()
	print("test_untyped_array: %dms" % (end_time - start_time))

func test_node_button_array():
	var a : Array[Node] = []
	var b := Button.new()
	var start_time = Time.get_ticks_msec()
	for i in 1000000:
		a.push_back(b)
	var end_time = Time.get_ticks_msec()
	print("test_node_button_array: %dms" % (end_time - start_time))

func test_node_node3d_array():
	var a : Array[Node] = []
	var n := Node3D.new()
	var start_time = Time.get_ticks_msec()
	for i in 1000000:
		a.push_back(n)
	var end_time = Time.get_ticks_msec()
	print("test_node_node3d_array: %dms" % (end_time - start_time))
	
func test_cast():
	var event : InputEvent = InputEventMouseMotion.new()
	var start_time = Time.get_ticks_msec()
	for i in 1000000:
		event as InputEventKey
	var end_time = Time.get_ticks_msec()
	print("test_cast: %dms" % (end_time - start_time))

Old

test_untyped_array: 89ms
test_node_button_array: 402ms
test_node_node3d_array: 242ms
test_cast: 508ms

New

test_untyped_array: 88ms
test_node_button_array: 155ms
test_node_node3d_array: 155ms
test_cast: 88ms

[dsnopek]

Thanks! This looks good to me :-)

[akien-mga]

Thanks!