libcore: rename private cmp macros

eq_impl! => partial_eq_impl!
totaleq_impl! => eq_impl!
ord_impl! => partial_ord_impl!
totalord_impl! => ord_impl!
auto merge of #16470 : liigo/rust/rename-private-cmp-macros, r=brson

eq_impl! => partial_eq_impl!
totaleq_impl! => eq_impl!
ord_impl! => partial_ord_impl!
totalord_impl! => ord_impl!