RFR [9]: 8072579: XjcOptionalPropertyTest.java creates files in test.src

[Aleks Efimov]

Hi,

Please, help to review XjcOptionalPropertyTest test modification bug [1].
The list of applied changes:
1. Test files are now generated in jtreg work directory (scratch), 
instead of test source folder.
2. Shell script was replaced with java code: xjc tool is now invoked via 
jdk.testlibrary.JDKToolLauncher.
3. Compilation of xjc generated classes is done with usage of 
JDKToolLauncher.

Webrev: http://cr.openjdk.java.net/~aefimov/8072579/9/00

With Best Regards,
Aleksej

[1] https://bugs.openjdk.java.net/browse/JDK-8072579