RFR: 8165600: Convert internal logging tests to GTest

[Marcus Larsson]

Hi,

Please review the following patch to convert existing internal VM tests 
for UL to the GTest framework.

Summary:
Most of it is just a simple conversion from assert() to ASSERT_*() 
macros. Tests which log to file, or otherwise change the log 
configuration, have been modified to use the LogTestFixture for 
automated log file handling and configuration cleanup.

Webrev:
http://cr.openjdk.java.net/~mlarsson/8165600/webrev.00/

Issue:
https://bugs.openjdk.java.net/browse/JDK-8165600

Testing:
JPRT

Thanks,
Marcus