RFR: 818269: Remove gcTrace.hpp include from referenceProcessor.hpp

[Stefan Karlsson]

Hi all,

Please review this trivial change to remove an include of gcTrace.hpp in 
referenceProcessor.hpp, and changes needed to get the code to compile 
after that.

http://cr.openjdk.java.net/~stefank/8182696/webrev.00/
https://bugs.openjdk.java.net/browse/JDK-8182696

I was prototyping ways to get more type safe time durations in HotSpot 
and found that whenever I changed my header file, that almost all 
HotSpot cpp files were recompiled. I tracked it down to come from the 
unused include of gcTrace.hpp in referenceProcessor.hpp.

We could probably also try to figure out why changes 
referenceProcessor.hpp triggers recompiles of the entire source code, 
but I'd like to leave that exercise for another day.

Thanks,
StefanK