PLUGIN_GGC_END, /* Called at end of GGC. */
PLUGIN_REGISTER_GGC_ROOTS, /* Register an extra GGC root table. */
PLUGIN_ATTRIBUTES, /* Called during attribute registration. */
+ PLUGIN_START_UNIT, /* Called before processing a translation unit. */
PLUGIN_EVENT_LAST /* Dummy event used for indexing callback
array. */
};