RFR(S): 8020107: Avoid crashes in WatcherThread

[Rickard Bäckman]

Hi all,

can I please have reviews for the following change?

We are adding a mechanism for avoiding some crashes in the WatcherThread using 
different OS-specific methods. 

Webrev: http://cr.openjdk.java.net/~rbackman/8020701/webrev/

Thanks
/R