Make trace dispatch purely a function of context rather than a function of both context and data. This lets us delete a lot of machinery for managing data-dependent tracing: levels, sublevels, post_process_call, new_base_main, custom_bind and so on.

Make trace dispatch purely a function of context rather than a function of both context and data. This lets us delete a lot of machinery for managing data-dependent tracing: levels, sublevels, post_process_call, new_base_main, custom_bind and so on. #2866