Add getXPathNodeName to the Node interface

A default implementation is available in AbstractNode
to preserve compatibility with the previous way, which
used Object.toString.

Fixes #569

pmd-plsql/src/main/java/net/sourceforge/pmd/lang/plsql/ast/AbstractPLSQLNode.java

@@ -64,6 +64,12 @@ public abstract class AbstractPLSQLNode extends net.sourceforge.pmd.lang.ast.Abs
         return data;
     }
 
+
+    @Override
+    public String getXPathNodeName() {
+        return PLSQLParserTreeConstants.jjtNodeName[id];
+    }
+
     /*
      * You can override these two methods in subclasses of SimpleNode to
      * customize the way the node appears when the tree is dumped. If your
@@ -72,7 +78,7 @@ public abstract class AbstractPLSQLNode extends net.sourceforge.pmd.lang.ast.Abs
      */
 
     public String toString() {
-        return PLSQLParserTreeConstants.jjtNodeName[id];
+        return getXPathNodeName();
     }
 
     public String toString(String prefix) {

pmd-plsql/src/main/java/net/sourceforge/pmd/lang/plsql/ast/DumpFacade.java

@@ -45,7 +45,7 @@ public class DumpFacade extends PLSQLParserVisitorAdapter {
         writer.print(prefix);
 
         // 2) JJT Name of the Node
-        writer.print(node.toString());
+        writer.print(node.getXPathNodeName());
 
         //
         // If there are any additional details, then: