bpo-33387: remove obsolete comment

6ca510d47497b0cf7f12ba5b7a0b145a952a9362
commit 6ca510d47497b0cf7f12ba5b7a0b145a952a9362
diff --git a/Python/compile.c b/Python/compile.c
@@ -898,8 +898,6 @@ compiler_next_instr(basicblock *b)
   * 1 -- when jump
   * -1 -- maximal
 */
-/* XXX Make the stack effect of WITH_CLEANUP_START and
-   WITH_CLEANUP_FINISH deterministic. */
static int
stack_effect(int opcode, int oparg, int jump)
{