RFR (S): 7117303: VM uses non-monotonic time source and complains that it is non-monotonic

[John Cuthbertson]

Hi Everyone,

Can I have a couple of volunteers review the changes for this CR? The 
webrev can be found at: http://cr.openjdk.java.net/~johnc/7117303/webrev.0/.

Summary:
I replaced the calls to os::javaTimeMillis() in the GC where we expect 
monotonicity with calls os::javaTimeNanos(), converting the result to 
milliseconds. os::javaTimeNanos(), at least on some configurations, does 
guarantee monotonicity and so is a better alternative. The changes in 
the os_<*> files are to make use of the named conversion constants I 
added/moved to globalDefinitions.hpp - we seemed to have multiple names 
for the same two constants.

Testing: GC test suite on solaris and Linux, NSK tests on solaris, and jprt.

Thanks,

JohnC