Enable recompilation of Uninterruptible and Unpreemptible code

The adaptive system currently only considers Interruptible methods for optimizing recompilation (see RecompilationStrategy.getPreviousCompiler).

This doesn't matter too much for opt compiled bootimages, but for prototype-opt it means that we'll never select any of the Uninterruptible/Unpreemptible methods in the bootimage for optimization compilation (in particular, pretty much all of MMTk is uninterruptible).

The reason we do this is that there are a very small number of uninterruptible bootimage methods whose PC's may have leaked out into the bootImageRunner. We should simply not do this any more (leak JTOC/TIB offsets instead) and force the C code to make the proper indirections to find the current compiled version. If we do this, then I believe we could remove the current hack in RecompilationStrategy.

We'll need to be a little careful to make sure that speculative optimizations aren't applied in uninterruptible code (to avoid getting ourselves backed into a corner where we no longer have a valid copy of a method that is needed to invalidate methods), but that should be fairly easy to do and is actually an independent issue of whether or not the code is uninterruptible.