Rewrite the stack

src/base.c

@@ -37,7 +37,7 @@ void *lisp_alloc_object(size_t size, LispValType type) {
         lisp_gc_yield(NULL, false);
     }
     if (the_stack.depth > 0) {
-        add_local_reference_no_recurse(obj);
+        add_local_reference_no_recurse(LISP_STACK_REF(), obj);
     }
     lisp_gc_register_object(obj);
     return obj;
@@ -74,6 +74,9 @@ noreturn void signal_type_error(LispVal *obj, LispVal *typespec) {
 DEFINE_SYMBOL(nil, "nil");
 DEFINE_SYMBOL(t, "t");
 DEFINE_SYMBOL(unbound, "unbound");
+DEFINE_SYMBOL(lexical_environment, "lexical-environment");
+
+LispVal *Vlexical_environment;
 
 DEFUN(id, "id", (LispVal * obj), "(id)", "") {
     // TODO not all values are handled here