Currently a scheme like __std_find_trivial -> __std_find_trivial_1/2/4/8 -> __std_find_trivial_impl
With these exceptions:

• Some like __std_reverse_trivially_swappable_1/2/4/8 don't have neither header dispatcher (so they are dispatched in multiple places), nor vector_algorithms.cpp common implementation
• Some .cpp implementations are unified under names _Minmax and _Minmax_element

Should we unify that?