RFR: JDK-8153273: Test lib compilations trigger find crash on Solaris

[Erik Joelsson]

As reported in JDK-8142906, find may crash when building the test-lib 
jars. This is caused by two SetupJavaCompilation setups putting their 
classes in the same directory. There is really no reason for them to do 
that so the fix is to use separate directories.

Bug: https://bugs.openjdk.java.net/browse/JDK-8153273
Webrev: http://cr.openjdk.java.net/~erikj/8153273/webrev.01/
/Erik