RFR: JDK-8114828: wrong class file error when compiling tests

[Alexander Kulyakhtin]

Hi,

Could you, please, review these simple test-only changes:

CR: https://bugs.openjdk.java.net/browse/JDK-8114828 "wrong class file error when compiling tests" 
(All the changed files belong to the Open JDK. Since the CR was submitted as confidential, the issue is described in this mail below)

Webrev: http://cr.openjdk.java.net/~akulyakh/8114828/index.html

Before the change the @library tags in the tests  pointed to the directory above the tests repository.
With the jtreg b12 and above this is not allowed. Instead, the external.lib.roots property should be used to specify any additional roots.  

The tests have been modified accordingly, so they now compile successfully.

Best regards,
Alexander