ignore test binaries
Take a single uintptr argument.
Allow a return value from JITed code, too.
We can assemble many forms of MOV!
Implement and test a bunch of arithmetic.

This caused us to run into some "fun" issues around operand width. Not
confident this is the right solution at all.
First pass at brainfuck.
gojit: Remove all assembly stubs.

Just chain directly to the JIT'd code -- we'll make it entirely their
responsibility to handle the golang ABI.

Add a BuildTo() helper to convert to an arbitrary-typed *func.
Use MAP_ANON

This is more portable, as it exists on both Linux and Darwin. closes #1.
Rework gojit/amd64 tests.
Fix the assembly of mov OFF(%rsp), %dst