async: a pending exception still fails zend_execute_script under a scheduler

Reporting stays deferred until after the scheduler drain, but the return
value now says FAILURE, so an uncaught exception in auto_prepend_file
stops the prepend/main/append chain like it does without a scheduler
instead of silently running the primary script with EG(exception) set.

Author: EdmondDantes

Zend/zend.c

@@ -1982,8 +1982,14 @@ ZEND_API zend_result zend_execute_script(int type, zval *retval, zend_file_handl
 				zend_user_exception_handler();
 			}
 
-			if (EG(exception) && ZEND_ASYNC_CURRENT_COROUTINE == NULL) {
-				ret = zend_exception_error(EG(exception), E_ERROR);
+			if (EG(exception)) {
+				if (ZEND_ASYNC_CURRENT_COROUTINE == NULL) {
+					ret = zend_exception_error(EG(exception), E_ERROR);
+				} else {
+					/* Report after the scheduler drain, but still break the
+					 * prepend/main/append chain. */
+					ret = FAILURE;
+				}
 			}
 		}
 		zend_destroy_static_vars(op_array);