Assert that _PUSH_FRAME is last in expansion

Author: gvanrossum

Python/optimizer.c

@@ -616,6 +616,7 @@ translate_bytecode_to_trace(
                         }
                         ADD_TO_TRACE(expansion->uops[i].uop, oparg, operand);
                         if (expansion->uops[i].uop == _PUSH_FRAME) {
+                            assert(i + 1 == nuops);
                             ADD_TO_TRACE(SAVE_IP, 0, 0);
                             goto done;
                         }