Implement interpreter VM using dynasm

[dibyendumajumdar]

My aim here is to implement a VM for x86-64 using dynasm. This is doable because of the fact that we can do most register allocations in a static manner.

The work is happening here: https://github.com/dibyendumajumdar/ravi/tree/master/vmbuilder

[dibyendumajumdar]

It is unlikely I will have the time to finish this. The benefits are not clear as the problem is elsewhere.

[dibyendumajumdar]

See #179