Remove unused param.
Rip out the guts! Removing many non-9k runtime classes.

* ClassCache is gone; it was hacky and problematic when compiled
  code held classloader-level (static) data, as when using indy
  call sites. Java 8 has also eliminated permgen, greatly reducing
  the hassle and overhead of loading jitted code. Finally, Rails
  and the other Ruby frameworks are now officially "thread safe"
  (or the teams are committed to them being so) and the multiple
  JRuby model of deployment is discouraged (or even deprecated).
* All old JIT code is gone. It won't be useful for the new
  JIT.
* Removed the last vestiges of Callback-based functions. If I
  remember right, there's some ext out there using them...we must
  find it.
* Rewired JITCompiler to use the new JIT.
* Rewired InterpretedIRMethod to use JITCompiler.
* Moved OneShotClassLoader out of ClassCache (in org.jruby.util)