8256154: Some TestNG tests require default constructors

Backport-of: 5ed7044

Author: GoeLin

test/jdk/java/lang/Package/GetPackages.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -55,6 +55,12 @@ public class GetPackages {
         this.fooClass = loader.loadClass("foo.Foo");
     }
 
+    /** For TestNG */
+    public GetPackages() {
+        loader = null;
+        fooClass = null;
+    }
+
     /*
      * Check package "foo" defined locally in the TestClassLoader
      * as well as its ancestors.

test/jdk/java/lang/StackWalker/Basic.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -111,6 +111,11 @@ public static void testMethodSignature() throws Exception {
         this.depth = depth;
     }
 
+    /** For TestNG */
+    public Basic() {
+        depth = 0;
+    }
+
     /*
      * Setup a stack builder with the expected stack depth
      * Walk the stack and count the frames.