GDScript: Fix "Identifier not found" error when accessing inner class from inside

modules/gdscript/tests/scripts/analyzer/features/inner_class_access_from_inside.gd

@@ -0,0 +1,21 @@
+# GH-80508
+
+class A:
+	func a():
+		return A.new()
+	func b():
+		return B.new()
+
+class B:
+	func a():
+		return A.new()
+	func b():
+		return B.new()
+
+func test():
+	var a := A.new()
+	var b := B.new()
+	print(a.a() is A)
+	print(a.b() is B)
+	print(b.a() is A)
+	print(b.b() is B)

modules/gdscript/tests/scripts/analyzer/features/inner_class_access_from_inside.out

@@ -0,0 +1,5 @@
+GDTEST_OK
+true
+true
+true
+true