Fix test for method type inference

Author: stanhebben

ScriptingEngineTester/src/main/resources/zencode-tests/type-inference/method-return-type-1.zc

@@ -1,12 +1,18 @@
 #output: hello
 #output: void
 
-class Foo {
-	print() {
+virtual class Foo {
+	print(): void {
 		println("hello");
 	}
 }
 
+class Bar : Foo {
+	override print() {
+		println("world");
+	}
+}
+
 new Foo().print();
 
 // expressions inside typeof will not be executed, so the print() won't be called