Use {$WEAKLINKRTTI ON}. Saves a lot of size and has no drawbacks it seems. Thanks to DRON.

Projects/Compil32.dpr

@@ -9,6 +9,8 @@ program Compil32;
   Compiler
 }
 
+{$WEAKLINKRTTI ON}
+
 uses
   SafeDLLPath in 'SafeDLLPath.pas',
   Windows,

Projects/ISCC.dpr

@@ -10,6 +10,8 @@ program ISCC;
   Command-line compiler
 }
 
+{$WEAKLINKRTTI ON}
+
 {x$DEFINE STATICCOMPILER}
 { For debugging purposes, remove the 'x' to have it link the compiler code
   into this program and not depend on ISCmplr.dll. }

Projects/ISCmplr.dpr

@@ -10,6 +10,8 @@ library ISCmplr;
   Compiler DLL
 }
 
+{$WEAKLINKRTTI ON}
+
 uses
   SafeDLLPath in 'SafeDLLPath.pas',
   SysUtils,

Projects/ISPP/ISPP.dpr

@@ -7,6 +7,7 @@
 library ISPP;
 
 {$IMAGEBASE $01800000}
+{$WEAKLINKRTTI ON}
 {$I ..\Version.inc}
 {$R *.RES}
 

Projects/Setup.dpr

@@ -2,15 +2,15 @@ program Setup;
 
 {
   Inno Setup
-  Copyright (C) 1997-2010 Jordan Russell
+  Copyright (C) 1997-2018 Jordan Russell
   Portions by Martijn Laan
   For conditions of distribution and use, see LICENSE.TXT.
 
   Setup program
-
-  $jrsoftware: issrc/Projects/Setup.dpr,v 1.76 2010/08/28 20:41:24 jr Exp $
 }
 
+{$WEAKLINKRTTI ON}
+
 uses
   SafeDLLPath in 'SafeDLLPath.pas',
   XPTheme in 'XPTheme.pas',

Projects/SetupLdr.dpr

@@ -2,13 +2,15 @@ program SetupLdr;
 
 {
   Inno Setup
-  Copyright (C) 1997-2010 Jordan Russell
+  Copyright (C) 1997-2018 Jordan Russell
   Portions by Martijn Laan
   For conditions of distribution and use, see LICENSE.TXT.
 
   Setup Loader
 }
 
+{$WEAKLINKRTTI ON}
+
 uses
   SafeDLLPath in 'SafeDLLPath.pas',
   XPTheme in 'XPTheme.pas',