Remove unnecessary PartialOrd constraint on new Rem implementation.
Remove unnecessary PartialOrd constraint on new Rem implementation.

rust-num/num-bigint,rust-num/num,rust-num/num-integer,rust-num/num,rust-lang/num,rust-lang/num,rust-num/num-integer,rust-num/num-traits,rust-num/num-traits,rust-num/num-bigint