Use MIR_PARALLEL_GEN instead of MIR_NO_PARALLEL_GEN.
@@ -6545,7 +6545,7 @@ void MIR_gen_finish (MIR_context_t ctx) {
void MIR_set_gen_interface (MIR_context_t ctx, MIR_item_t func_item) {
struct all_gen_ctx *all_gen_ctx = *all_gen_ctx_loc (ctx);
-#ifdef MIR_NO_PARALLEL_GEN
+#if !MIR_PARALLEL_GEN
if (func_item == NULL) return; /* finish setting interfaces */
MIR_gen (ctx, 0, func_item);
#else
