sdStreams unit is not compatible with x64

[DenisAnisimov]

line 141: Move(Pointer(Longint(FMemory) + FPosition)^, Buffer, Result);

must be Move(Pointer(NativeUInt(FMemory) + UInt32(FPosition))^, Buffer, Result)

Line 218: System.Move(Buffer, Pointer(Longint(FMemory) + FPosition)^, Count);

must be System.Move(Buffer, Pointer(NativeUInt(FMemory) + UInt32(FPosition))^, Count);