RFR: JDK-8028631 - Improve the test coverage to the pathname handling on unix-like platforms

[Dan Xu]

Hi All,

We have java/io/pathNames/GeneralWin32.java testcase to do the general 
exhaustive test of pathname handling on windows. I am adding a new test 
GeneralSolaris.java to test the pathname handling in unix-like 
platforms. In the changes, I also make sure the test can run 
successfully in concurrency mode. Please help review it. Thanks!

Bug: https://bugs.openjdk.java.net/browse/JDK-8028631
Webrev: http://cr.openjdk.java.net/~dxu/8028631/webrev/

-Dan