Turn on -Winconsistent-missing-override
Track some stats about the memory we allocate for the JIT
simple 'benchmark suite'
Print the geometric mean
Make the GCVisitor non-virtual for a small speedup
Some refactoring for some GC changes
Set the mark-bit when pushing onto the stack, instead of when popping off

Good for a 10-15% speedup

I still feel like we can do much better here though