remove superfluous derives from numbers

src/value/number/integer.rs

@@ -7,7 +7,6 @@ use std::{
 use num_bigint::BigInt;
 use num_traits::{Signed, ToPrimitive, Zero};
 
-#[derive(Eq, PartialEq)]
 pub(crate) enum Integer {
     Small(i64),
     Big(BigInt),
@@ -113,10 +112,6 @@ impl Zero for Integer {
             Self::Big(v) => v.is_zero(),
         }
     }
-
-    fn set_zero(&mut self) {
-        *self = Self::zero()
-    }
 }
 
 impl Display for Integer {

src/value/number/mod.rs

@@ -226,7 +226,7 @@ impl Num for Number {
     type FromStrRadixErr = ();
     #[cold]
     fn from_str_radix(_: &str, _: u32) -> Result<Self, Self::FromStrRadixErr> {
-        unreachable!()
+        unimplemented!()
     }
 }
 
@@ -237,7 +237,7 @@ impl Signed for Number {
 
     #[cold]
     fn abs_sub(&self, _: &Self) -> Self {
-        unreachable!()
+        unimplemented!()
     }
 
     #[cold]