8165451: Convert WorkerDataArray_test to GTest
Reviewed-by: jwilhelm

8152952: Allow G1 phase logging to use individual number of threads
Reviewed-by: tschatzl, jmasa

8150068: Log the main G1 phases at info level
Reviewed-by: sjohanss, tschatzl

8145092: Use Unified Logging for the GC logging
Summary: JEP-271. VM changes contributed by brutisso, test changes contributed by david.
Reviewed-by: sjohanss, david, brutisso
Contributed-by: bengt.rutisson@oracle.com, david.lindholm@oralce.com

8140393: Move WorkerDataArray to its own file
Reviewed-by: tschatzl, mgerdin, tbenson