GDScript: Fix and simplify coroutine stack clearing

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

@@ -1,13 +1,16 @@
-# GH-116706
-
 class Instance:
 	func _init() -> void:
 		print("Instance _init")
 
+	func _to_string() -> String:
+		return "<Instance>"
+
 	func _notification(what: int) -> void:
 		if what == NOTIFICATION_PREDELETE:
 			print("Instance predelete")
 
+# GH-116706
+
 class LocalOwner:
 	signal never_emitted()
 
@@ -24,10 +27,52 @@ class LocalOwner:
 		await never_emitted
 		print("interrupted_coroutine end")
 
-func test():
-	print("test begin")
+func subtest_order():
+	print("subtest_order begin")
 	var local_owner := LocalOwner.new()
 	@warning_ignore("missing_await")
 	local_owner.interrupted_coroutine()
 	local_owner = null
-	print("test end")
+	print("subtest_order end")
+
+# GH-117049
+
+signal tick()
+
+func await_before_and_after() -> void:
+	await tick
+	var packed_array: PackedStringArray = ["abc"]
+	var instance := Instance.new()
+	await tick
+	prints(packed_array, instance)
+
+func await_two_after() -> void:
+	var packed_array: PackedStringArray = ["abc"]
+	var instance := Instance.new()
+	await tick
+	await tick
+	prints(packed_array, instance)
+
+func subtest_resume():
+	print("subtest_resume begin")
+
+	@warning_ignore("missing_await")
+	await_before_and_after()
+	tick.emit()
+	tick.emit()
+
+	print("---")
+
+	@warning_ignore("missing_await")
+	await_two_after()
+	tick.emit()
+	tick.emit()
+
+	print("subtest_resume end")
+
+# ===
+
+func test():
+	subtest_order()
+	print("===")
+	subtest_resume()

modules/gdscript/tests/scripts/runtime/features/coroutine_clearing.out

@@ -1,8 +1,18 @@
 GDTEST_OK
-test begin
+subtest_order begin
 LocalOwner _init
 interrupted_coroutine begin
 Instance _init
 LocalOwner predelete
 Instance predelete
-test end
+subtest_order end
+===
+subtest_resume begin
+Instance _init
+["abc"] <Instance>
+Instance predelete
+---
+Instance _init
+["abc"] <Instance>
+Instance predelete
+subtest_resume end