Remove dead codes in core

Author: mu001999

library/core/src/fmt/num.rs

@@ -15,8 +15,6 @@ trait DisplayInt:
     fn zero() -> Self;
     fn from_u8(u: u8) -> Self;
     fn to_u8(&self) -> u8;
-    fn to_u16(&self) -> u16;
-    fn to_u32(&self) -> u32;
     fn to_u64(&self) -> u64;
     fn to_u128(&self) -> u128;
 }
@@ -27,8 +25,6 @@ macro_rules! impl_int {
           fn zero() -> Self { 0 }
           fn from_u8(u: u8) -> Self { u as Self }
           fn to_u8(&self) -> u8 { *self as u8 }
-          fn to_u16(&self) -> u16 { *self as u16 }
-          fn to_u32(&self) -> u32 { *self as u32 }
           fn to_u64(&self) -> u64 { *self as u64 }
           fn to_u128(&self) -> u128 { *self as u128 }
       })*
@@ -40,8 +36,6 @@ macro_rules! impl_uint {
           fn zero() -> Self { 0 }
           fn from_u8(u: u8) -> Self { u as Self }
           fn to_u8(&self) -> u8 { *self as u8 }
-          fn to_u16(&self) -> u16 { *self as u16 }
-          fn to_u32(&self) -> u32 { *self as u32 }
           fn to_u64(&self) -> u64 { *self as u64 }
           fn to_u128(&self) -> u128 { *self as u128 }
       })*