message: Removed some clippy warnings in memcpy, memmove, memcmp
diff: pub unsafe extern "C" fn memcpy(dest: *mut u8, src: *const u8, n: usize) -> *mut u8 {
  let mut i = 0;
  while i < n {
  - *dest.offset(i as isize) = *src.offset(i as isize);
  + *dest.add(i) = *src.add(i);
  i += 1;
  }
  - return dest;
  + dest
  }
  #[no_mangle]
  @@ -32,41 +32,41 @@ pub unsafe extern "C" fn memmove(dest: *mut u8, src: *const u8, n: usize) -> *mu
  let mut i = n;
  while i != 0 {
  i -= 1;
  - *dest.offset(i as isize) = *src.offset(i as isize);
  + *dest.add(i) = *src.add(i);
  }
  } else {
  // copy from beginning
  let mut i = 0;
  while i < n {
  - *dest.offset(i as isize) = *src.offset(i as isize);
  + *dest.add(i) = *src.add(i);
  i += 1;
  }
  }
  - return dest;
  + dest
  }
  #[no_mangle]
  pub unsafe extern "C" fn memset(s: *mut u8, c: i32, n: usize) -> *mut u8 {
  let mut i = 0;
  while i < n {
  - *s.offset(i as isize) = c as u8;
  + *s.add(i) = c as u8;
  i += 1;
  }
  - return s;
  + s
  }
  #[no_mangle]
  pub unsafe extern "C" fn memcmp(s1: *const u8, s2: *const u8, n: usize) -> i32 {
  let mut i = 0;
  while i < n {
  - let a = *s1.offset(i as isize);
  - let b = *s2.offset(i as isize);
  + let a = *s1.add(i);
  + let b = *s2.add(i);
  if a != b {
  return a as i32 - b as i32;
  }
  i += 1;
  }
  - return 0;
  + 0
  }
  #[cfg(test)]
  