Make NonZero<char> possible

Author: hkBst

library/core/src/num/niche_types.rs

@@ -131,6 +131,8 @@ define_valid_range_type! {
     pub struct NonZeroI32Inner(i32 as u32 in 1..=0xffff_ffff);
     pub struct NonZeroI64Inner(i64 as u64 in 1..=0xffffffff_ffffffff);
     pub struct NonZeroI128Inner(i128 as u128 in 1..=0xffffffffffffffff_ffffffffffffffff);
+
+    pub struct NonZeroCharInner(char as u32 in 1..=0x10ffff);
 }
 
 #[cfg(target_pointer_width = "16")]

library/core/src/num/nonzero.rs

@@ -79,6 +79,7 @@ impl_zeroable_primitive!(
     NonZeroI64Inner(i64),
     NonZeroI128Inner(i128),
     NonZeroIsizeInner(isize),
+    NonZeroCharInner(char),
 );
 
 /// A value that is known not to equal zero.