RFR: 5049299 - (process) Use,posix_spawn, not fork, on S10 to avoid swap,exhaustion (jdk7u-dev)

[Rob McKenna]

Hi folks,

I'd like to backport this change to JDK7. Note: this fix uses 
posix_spawn by default on Mac OSX only. On Solaris fork will remain the 
default behaviour.

I've just noticed that there is a problem with the testcase on Solaris 
in that it will test fork twice. (and won't test posix_spawn) I'll 
figure out a way around this, but in the mean time I'd like to get the 
ball rolling on this review anyway.

    -Rob