a) We specialize opcodes according to op_type fields. Each opcode has to
be marked with which op_type's it uses.
b) We support different execution methods. Function handlers, switch()
and goto dispatching. goto seems to be the fastest but it really
depends on the compiler and how well it optimizes. I suggest playing
around with optimization flags.
- Warning: Things might break so keep us posted on how things are going.
(Dmitry, Andi)
