feat(compiler): Streamlined reference counting (#1714)

* feat(compiler): Streamlined reference counting

* snapshots

* Use stable ordering for gc pass

* no block

* rename block_ans

* refactor closure arguments

* new snapshots

Author: ospencer

compiler/src/codegen/compcore.re

@@ -6,6 +6,7 @@ open Binaryen;
 type codegen_env = {
   name: option(string),
   num_args: int,
+  num_closure_args: int,
   stack_size,
   /* Allocated closures which need backpatching */
   backpatches: ref(list((Expression.t, closure_data))),