Java: Add initial version of empty method query

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

@@ -0,0 +1,29 @@
+import org.aspectj.lang.annotation.Pointcut;
+
+public class Test {
+
+    // COMPLIANT
+    public void f() {
+        int i = 0;
+    }
+
+    // COMPLIANT
+    public void f1() {
+        // intentionally empty
+    }
+
+    // NON_COMPLIANT
+    public void f2() {}
+
+    // COMPLIANT - exception
+    @Pointcut()
+    public void f4() {}
+
+    public abstract class TestInner {
+
+        public abstract void f(); // COMPLIANT - intentionally empty
+    }
+
+}
+
+