TestShutdownCompleteNEWT: Enhance profiling via '-wait -initOnly' ; Use Platform.currentTimeMicros() for accuracy

ReflectionUtil usage:

TestShutdownCompleteNEWT -wait -initOnly

Hotspots:
   - MakeCurrent 5.3% - Called 52 times
   - ClassLoader.findClass(..) 3.1% - Called 486 times .
      - ReflectionUtil: 13 times ~ 0.3%