*   `GraphOptions.skip_common_subexpression_elimination` has been removed. All
    graph optimizer options are now specified via
    `GraphOptions.OptimizerOptions`.
*   `ASSERT_OK` / `EXPECT_OK` macros conflicted with external projects, so they
    were renamed `TF_ASSERT_OK`, `TF_EXPECT_OK`. The existing macros are
    currently maintained for short-term compatibility but will be removed.