RFR: 8157449: Adjust link-time generated Species classes to match JDK-8148604 usage

[Claes Redestad]

Hi,

I noticed that the BMH$Species classes generated at link time slightly 
mismatch the classes generated when concatenating things. Updating this 
to match reality helps mitigate a small fraction of the startup penalty 
to enabling the optimal string concatenation strategy:

Bug: https://bugs.openjdk.java.net/browse/JDK-8157449
Webrev: http://cr.openjdk.java.net/~redestad/8157449/webrev.00/

Note that the plan is to generate this list of defaults automatically in 
a profiling step, either during build or as part of the ongoing 
development process. Apologies for not having gotten to that yet. :-)

Thanks!

/Claes