[Bug d/113772] [14 Regression] atomic.d compile error since recent upstream imports.

["ibuclaw at gdcproject dot org" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113772

--- Comment #4 from Iain Buclaw <ibuclaw at gdcproject dot org> ---
Looking at gcc/builtins.cc, I have a bad feeling that the only compile-time
values one can get out of this built-in are "true" and "defer to run-time"

---
/* Return a one or zero if it can be determined that object ARG1 of size ARG 
   is lock free on this architecture.  */

static tree
fold_builtin_atomic_is_lock_free (tree arg0, tree arg1)
{
  if (!flag_inline_atomics)
    return NULL_TREE;

  /* If it isn't always lock free, don't generate a result.  */
  if (fold_builtin_atomic_always_lock_free (arg0, arg1) == boolean_true_node)
    return boolean_true_node;

  return NULL_TREE;
} 
---

The upstream contributor who tested this on x86 likely didn't get this because
it's all lock-free.