py: Improve efficiency of MP_OBJ_IS_STR_OR_BYTES.
Saves ROM (16 on stmhal, 240 on 64-bit unix) and should be quicker since
there is 1 less branch.
diff --git a/py/obj.h b/py/obj.h
index 4f32a80..7bf00d4 100644
--- a/py/obj.h
+++ b/py/obj.h
@@ -74,7 +74,7 @@
#define MP_OBJ_IS_TYPE(o, t) (MP_OBJ_IS_OBJ(o) && (((mp_obj_base_t*)(o))->type == (t))) // this does not work for checking int, str or fun; use below macros for that
#define MP_OBJ_IS_INT(o) (MP_OBJ_IS_SMALL_INT(o) || MP_OBJ_IS_TYPE(o, &mp_type_int))
#define MP_OBJ_IS_STR(o) (MP_OBJ_IS_QSTR(o) || MP_OBJ_IS_TYPE(o, &mp_type_str))
-#define MP_OBJ_IS_STR_OR_BYTES(o) (MP_OBJ_IS_STR(o) || MP_OBJ_IS_TYPE(o, &mp_type_bytes))
+#define MP_OBJ_IS_STR_OR_BYTES(o) (MP_OBJ_IS_QSTR(o) || (MP_OBJ_IS_OBJ(o) && ((mp_obj_base_t*)(o))->type->binary_op == mp_obj_str_binary_op))
#define MP_OBJ_IS_FUN(o) (MP_OBJ_IS_OBJ(o) && (((mp_obj_base_t*)(o))->type->binary_op == mp_obj_fun_binary_op))
#define MP_OBJ_SMALL_INT_VALUE(o) (((mp_int_t)(o)) >> 1)