[7u8] Request for approval: 7168172: (fs) Files.isReadable slow on Windows

[Kurchi Hazra]

This is a request for approval to backport the fix for 7168172 from 8 to 7u8.

Bug:http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7168172
Webrev:http://cr.openjdk.java.net/~khazra/7168172/7u8/webrev.00/

This had been reviewed by Alan Bateman, Ulf Zibis and Zhong 
Yu(zhong.j...@gmail.com). [1]

This fix has been pushed into jdk8 [2]. The fix for 7u8 is identical.

Thanks,
Kurchi

[1]http://mail.openjdk.java.net/pipermail/nio-dev/2012-August/001847.html
[2]http://hg.openjdk.java.net/jdk8/tl/jdk/rev/bd91a601265c