CR 6860309 - solaris timing issue on thread startup

[Gary Adams]

  CR 6860309 - TEST_BUG: Insufficient sleep time in 
java/lang/Runtime/exec/StreamsSurviveDestroy.java

A timing problem is reported for slow solaris systems for this
test to start up a process and systematically torture the underlying
threads processing data from the running process.

On my fast solaris machine I can not reproduce the error,
but it is reasonable to assume that on a slower machine there
could be scheduling issues that could delay the thread startup
past the designated 100 millisecond delay in the main thread.

This webrev suggests gating the process destruction until both
worker threads are alive.

   http://cr.openjdk.java.net/~gadams/6860309/