Revise benchmarks:

- Ditch JS since it's in a different league.
- Make binary_trees and fib run faster.
- Compare using best time instead of mean.
Move OP_CLOSURE and OP_LIST down.

Since they're less frequently used, pushing them down speeds
things up a little bit.
Get basic superclass method calls working.
Special "constructor methods" -> "new" instruction.

This simplifies the call instruction a bit (and is overall
less code).