Ntdll.dll is NOT synced with WINE, it is made by ReactOS (source)
The Native API Architecture is implemented in NTDLL.dll. Aside from containing Native API user mode entry points, NTDLL.dll also contains process startup and module loading code.
NTDLL contains part of the Native API, including the C Run Time Library (RTL) api.
- wikipedia:Native API : Rtl is the second largest group of ntdll calls. These comprise the (extended) C Run-Time Library, which includes many utility functions that can be used by native applications, yet don't directly involve kernel support.
- wikipedia:Microsoft Windows library files#Ntdll.dll