Add compliant/non-compliant comments back to the test file

Author: tamasvajk

java/ql/test/query-tests/EmptyMethod/EmptyMethod.expected

@@ -1,2 +1,2 @@
-| Test.java:13:15:13:16 | f2 | This empty method should be completed. |
-| Test.java:35:18:35:23 | method | This empty method should be completed. |
+| Test.java:16:15:16:16 | f2 | This empty method should be completed. |
+| Test.java:43:18:43:23 | method | This empty method should be completed. |

java/ql/test/query-tests/EmptyMethod/Test.java

@@ -2,36 +2,44 @@
 
 public class Test {
 
+  // COMPLIANT
   public void f() {
     int i = 0;
   }
 
+  // COMPLIANT
   public void f1() {
     // intentionally empty
   }
 
+  // NON_COMPLIANT
   public void f2() { } // $ Alert
 
+  // COMPLIANT - exception
   @Pointcut()
   public void f4() {
   }
 
   public abstract class TestInner {
 
-    public abstract void f();
+    public abstract void f(); // COMPLIANT - intentionally empty
+
   }
 
   public class Derived extends TestInner {
 
+    // COMPLIANT: with annotation
     @Override
     public void f() {
     }
 
+    // COMPLIANT: native
     public native int nativeMethod();
   }
 
   public interface TestInterface {
 
+    // NON_COMPLIANT
     default void method() { } // $ Alert
   }