message: Use c_char instead of i8
diff: @@ -1284,7 +1284,7 @@ impl<'tu, 'ge> TypeRef<'tu, 'ge> {
  return format!("u8::try_from({name})?", name=name);
  }
  Some(Signedness::Signed) => {
  - return format!("u8::try_from({name})? as i8", name=name);
  + return format!("u8::try_from({name})? as c_char", name=name);
  }
  None => {}
  }
  