8250578: Address reliance on default constructors in javax.sql

Reviewed-by: lancea

src/java.sql.rowset/share/classes/javax/sql/rowset/RowSetMetaDataImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2003, 2014, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 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
@@ -52,6 +52,10 @@ import java.lang.reflect.*;
  * @since 1.5
  */
 public class RowSetMetaDataImpl implements RowSetMetaData,  Serializable {
+    /**
+     * Constructs a {@code RowSetMetaDataImpl} object.
+     */
+    public RowSetMetaDataImpl() {}
 
     /**
      * The number of columns in the <code>RowSet</code> object that created