InstanceSize method returns 16 on Linux and Mac. Windows - 8.
Class fields - Single, Pointer, Pointer, SizeInt, LongInt.
Who can explain?
Compiler options - -O3 -XX -CX.
Linux -
Free Pascal Compiler version 3.0.0+dfsg-2 [2016/01/28] for x86_64
Copyright (c) 1993-2015 by Florian Klaempfl and others
Target OS: Linux for x86-64
Mac -
Free Pascal Compiler version 3.0.4 [2018/10/02] for x86_64
Copyright (c) 1993-2017 by Florian Klaempfl and others
Target OS: Darwin for x86_64
Windows -
Free Pascal Compiler version 3.3.1-r20:43504 [2019/11/17] for i386
Copyright (c) 1993-2019 by Florian Klaempfl and others
Target OS: Win32 for i386