Seems like there are two parts to it

1. make sure all the methods are there e.g. there is bcs::native_to_bytes in both move/move-native as well as sui/move/move-native so we count it as being there
2. make sure all the methods implement the same thing. Most methods in sui have been modified for the cost/gas calculations. We can do this in a follow up step once the migration is complete.

For step#1.

Comparing all the files.

ls sui/external-crates/move/crates/move-stdlib/src/natives/
bcs.rs       debug.rs     hash.rs      helpers.rs   mod.rs       signer.rs    string.rs    type_name.rs unit_test.rs vector.rs

ls move/language/move-stdlib/src/natives/
bcs.rs       event.rs     helpers.rs   signer.rs    type_name.rs vector.rs
debug.rs     hash.rs      mod.rs       string.rs    unit_test.rs

Seems like move/move-stdlib has one extra file event.rs

Comparing for presence of methods in these files. Methods should at least have the same signature.

• bcs.rs
• debug.rs
  • New functions: native_print_nop, native_print_stack_trace_nop
  • Different signatures: make_native_print, make_native_print_stack_trace, make_all
  • Others: Change in scope of some imported types like MoveStructLayout etc.
• hash.rs
• helpers.rs
• mod.rs
  • New functions: unit_test:PoisionGasParameters
• signer.rs
• string.rs
• type_name.rs
  • New functions: make_native_get
  • Different signatures: native_get
• unit_test.rs
  • New functions: native_poison, make_native_poison
  • Others: New class PoisonGasParameters, GasParameters has one more param poison
• vector.rs

There are two native functions that are absent in move-language/move(after checking out @brson's updated branch)

// from crates/mysten-util-mem/src/allocators.rs
// Linux/BSD call system allocator (currently malloc).
pub unsafe extern "C" fn malloc_usable_size(_ptr: *const c_void) -> usize

// from crates/mysten-util-mem/src/malloc_size.rs
pub type VoidPtrToSizeFn = unsafe extern "C" fn(ptr: *const c_void) -> usize

This is used for calling size_of for various allocations. All the various size_of implementations are in https://github.com/MystenLabs/sui/tree/main/crates/mysten-util-mem.

Do we still want to implement(import) them in move-native?