push_n_(codegen_scope *s, int n)
{
  if (s->sp+n >= 0xffff) {
    codegen_error(s, "too complex expression");
  }
  s->sp+=n;
  nregs_update;
}
push_n_(codegen_scope *s, int n)
{
  if (s->sp+n >= 0xffff) {
    codegen_error(s, "too complex expression");
  }
  s->sp+=n;
  nregs_update;
}