RFR: 8219149: ProcessTools.ProcessBuilder should print timing info for subprocesses

[Kim Barrett]

> On May 30, 2019, at 3:58 PM, Roger Riggs <Roger.Riggs at oracle.com> wrote:
> 
> Hi Kim,
> 
> To ensure you see some messages in the case of timeouts, it would be
> useful to call System.out.flush() after printing the message in logProcess().

Good idea; added.

full: http://cr.openjdk.java.net/~kbarrett/8219149/open.01/
incr: http://cr.openjdk.java.net/~kbarrett/8219149/open.01.inc/

> I'm ok with the timestamps, as is, though the Duration might be useful in
> some cases.

As I discussed with Roger, I want to keep the change simple for now,
as we're not yet sure where to expend effort looking deeper.  I think
comparing timestamps in just a few cases will tell us a lot (possibly
that we're looking in entirely the wrong place, in which case we might
just undo this change).