Just in case you are maintaining Delphi code for several older versions of Delphi: Be aware that the declarations of NativeInt and NativeUInt are wrong in some of them.
|Delphi version||SizeOf(Native(U)Int) Win32||SizeOf(Native(U)Int) Win64|
|1 to 6||not available||not available|
|7 to 2007||
8 ← this is wrong
|2009 to XE||4||not available|
|XE2 to XE8||4||8|
I just stumbled over this in GExperts, which had a wrong IFDEF for overwriting that declaration.