GDScript: Allow supertype objects to be assigned to a subtype variable

It allows `get_node()` to be used with typed variables

This is marked as unsafe to warn the user.

modules/gdscript/gdscript_analyzer.cpp

@@ -498,7 +498,13 @@ void GDScriptAnalyzer::resolve_class_interface(GDScriptParser::ClassNode *p_clas
 
 					if (member.variable->initializer != nullptr) {
 						if (!is_type_compatible(datatype, member.variable->initializer->get_datatype(), true)) {
-							push_error(vformat(R"(Value of type "%s" cannot be assigned to a variable of type "%s".)", member.variable->initializer->get_datatype().to_string(), datatype.to_string()), member.variable->initializer);
+							// Try reverse test since it can be a masked subtype.
+							if (!is_type_compatible(member.variable->initializer->get_datatype(), datatype, true)) {
+								push_error(vformat(R"(Value of type "%s" cannot be assigned to a variable of type "%s".)", member.variable->initializer->get_datatype().to_string(), datatype.to_string()), member.variable->initializer);
+							} else {
+								// TODO: Add warning.
+								mark_node_unsafe(member.variable->initializer);
+							}
 						} else if (datatype.builtin_type == Variant::INT && member.variable->initializer->get_datatype().builtin_type == Variant::FLOAT) {
 #ifdef DEBUG_ENABLED
 							parser->push_warning(member.variable->initializer, GDScriptWarning::NARROWING_CONVERSION);
@@ -994,7 +1000,13 @@ void GDScriptAnalyzer::resolve_variable(GDScriptParser::VariableNode *p_variable
 
 		if (p_variable->initializer != nullptr) {
 			if (!is_type_compatible(type, p_variable->initializer->get_datatype(), true)) {
-				push_error(vformat(R"(Value of type "%s" cannot be assigned to a variable of type "%s".)", p_variable->initializer->get_datatype().to_string(), type.to_string()), p_variable->initializer);
+				// Try reverse test since it can be a masked subtype.
+				if (!is_type_compatible(p_variable->initializer->get_datatype(), type, true)) {
+					push_error(vformat(R"(Value of type "%s" cannot be assigned to a variable of type "%s".)", p_variable->initializer->get_datatype().to_string(), type.to_string()), p_variable->initializer);
+				} else {
+					// TODO: Add warning.
+					mark_node_unsafe(p_variable->initializer);
+				}
 #ifdef DEBUG_ENABLED
 			} else if (type.builtin_type == Variant::INT && p_variable->initializer->get_datatype().builtin_type == Variant::FLOAT) {
 				parser->push_warning(p_variable->initializer, GDScriptWarning::NARROWING_CONVERSION);
@@ -1385,9 +1397,16 @@ void GDScriptAnalyzer::reduce_assignment(GDScriptParser::AssignmentNode *p_assig
 			compatible = is_type_compatible(p_assignment->assignee->get_datatype(), op_type, true);
 			if (!compatible) {
 				if (p_assignment->assignee->get_datatype().is_hard_type()) {
-					push_error(vformat(R"(Cannot assign a value of type "%s" to a target of type "%s".)", p_assignment->assigned_value->get_datatype().to_string(), p_assignment->assignee->get_datatype().to_string()), p_assignment->assigned_value);
+					// Try reverse test since it can be a masked subtype.
+					if (!is_type_compatible(op_type, p_assignment->assignee->get_datatype(), true)) {
+						push_error(vformat(R"(Cannot assign a value of type "%s" to a target of type "%s".)", p_assignment->assigned_value->get_datatype().to_string(), p_assignment->assignee->get_datatype().to_string()), p_assignment->assigned_value);
+					} else {
+						// TODO: Add warning.
+						mark_node_unsafe(p_assignment);
+					}
 				} else {
 					// TODO: Warning in this case.
+					mark_node_unsafe(p_assignment);
 				}
 			}
 		} else {