RFR (S): Recognize windows 8

[Mikael Vidstedt]

This change adds support for recognizing Windows 8 in 
os::print_windows_version, inspired by the corresponding changes in the 
libraries [1][2].

Verified on a Windows 8 machine and passes JPRT.

http://cr.openjdk.java.net/~mikael/7170275/webrev.00

Please help me review, and I'll also be needing a sponsor.

Thanks,
Mikael

[1] http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=7170169
[2] http://cr.openjdk.java.net/~khazra/7170169/7u6/webrev.00