[Jamvm-general] add support for darwin / x86_64

[Christopher F. <chr...@gm...>]

Hi jamvm list,

Here is some basic support for darwin / x86_64. It's mainly duplicating 
some code made by Robert. This is verified to the extent that it Works 
For Me™ and I've tested it with some other subsequent changes.

I've cloned jamvm on github as well, and added a couple of branches for 
experimentation.

If you want to look at this patch pretty-printed, then follow the link 
below.

https://github.com/cfriedt/jamvm/compare/darwin-x86-64

Cheers,

C