RFR: JDK-8215544: SA: Modify ClhsdbLauncher to add sudo privileges to enable MacOS tests on Mach5

[Jini George]

Hello!

Requesting reviews for:

https://bugs.openjdk.java.net/browse/JDK-8215544
Webrev: http://cr.openjdk.java.net/~jgeorge/8215544/webrev.03/index.html

The changes here are primarily for modifying the ClhsdbLauncher used for 
SA tests to check if 'sudo' privileges can be added for executing MacOS 
tests, and if so, adding these privileges before executing the tests. 
This is related to the changes which were proposed with:

http://mail.openjdk.java.net/pipermail/serviceability-dev/2018-July/024373.html

for (JDK-8199700: SA: Enable jhsdb jtreg tests for Mac OS X).

The issue brought out with the proposed changes for JDK-8199700 have 
been fixed. This patch addresses the case where 'sudo' fails with errors 
like:

sudo: no tty present and no askpass program specified
  or
sudo: a password is required

or if 'sudo' waits for a password. In these cases, the tests continue to 
get skipped.

Many thanks to Goetz Lindenmaier for helping me with multiple rounds of 
testing of this in the SAP test farms! With this patch, about 22 SA 
tests get enabled now on MacOS on Mach5.

More details at: https://bugs.openjdk.java.net/browse/JDK-8215544

Thanks,
Jini.