A port of Jonesforth that I wrote in x86-64 assembly, circa Sept 2018.

• link to glibc (there's no point in making a standalone executable if you're using linux syscalls anyways, lot of wasted effort)
• safety checks are important in real programs
• choose registers carefully, current register choice conflicts with passing parameters

• use clone() to spawn forth interpreters in seperate threads!
  • really cheap to create and destroy!
  • allocate memory dynamically for this to work well
• ALLOC and related calls do not allocate more memory if we run out
• profiling does not work, as we need the stdlib exit(2) to work to generate a gmon.out
• assembler is not working yet.
• architecture of main.S is limiting the things I can do to make this better.
  • a complete re-write would be in order.
  • use r14 and r15 to hold state
  • use sse and cmov