add new compiler infrastructure
begin adding codegen usage example, adapted from llvm's kaleidoscope
begin implementing kaleidoscope Ast
more kaleidoscope work
fix linux cmake build
more kaleidoscope work
read data from console
fix kaleidoscope chapter 1/2
begin implementing codegen in kaleidoscope
more kaleidoscope codegen work
fix kaleidoscope parsing
intermediate work in kaleidoscope
fix several kaleidoscope undefined reference errors
split out ffi::call from System
compile all targets in cmake