Made meta_op_t be meta_op_term_t.
Got rid of is_deterministic_impl.
Removed the backtrace_t::push_back helper function.
Removed unused dummy_frames argument from fourth exc_t constructor.
Removed unused dummy_frames parameter from runtime_check and the second exc_t constructor.
Turned runtime_check into runtime_fail.
Removed a bunch of unnecessary unreachable()s.
Used UNUSED in a place.
Put r_sanity_check conditional in macro.
Made datum_term_t check that it has a valid protobuf.
Removed pb_rcheckable_t constructor that takes a Term.
Made datum_stream_t and eager_datum_stream_t constructors be protected.
Made func_t constructor be protected.
Made val_t constructor not take scope_env_t, take env_t instead.
Made datum_t not inherit from rcheckable_t.
Removed virtual destructor from home_thread_mixin_t.
Renamed merge_res_f to merge_resoluter_t.
Made check_has, check_not_has, check_empty macros in validate.cc not concatenate together method names.
Made check_has, check_not_has, and check_empty avoid reevaluating their "pb" parameters.
Removed pointless datum_term_t check.