RFR 8068306, 8068304, 8068303 : Tests for JEP 236: Parser API for Nashorn

[Sergey Lugovoy]

Hi all,
Please review http://cr.openjdk.java.net/~slugovoy/8068306/webrev.01/ 
for  JEP 236: Parser API for Nashorn

JEP :  https://bugs.openjdk.java.net/browse/JDK-8058809
Test tasks :

 * Tests for Diagnostic listener for Nashorn Parser API -
   https://bugs.openjdk.java.net/browse/JDK-8068304
 * Tests for AST presentation Nashorn Parser API -
   https://bugs.openjdk.java.net/browse/JDK-8068306
 * Create tests for Nashorn Parser API for create Tree from some
   different source and parameters -
   https://bugs.openjdk.java.net/browse/JDK-8068303


--
Thanks,
Sergey