Tweak for Windows.

git-svn-id: https://svn.r-project.org/R/trunk@87870 00db46b3-68df-0310-9c12-caf00c1e9a41

src/include/Startup.h

@@ -1,6 +1,6 @@
 /*
  *  R : A Computer Language for Statistical Data Analysis
- *  Copyright (C) 1999-2020  The R Core Team
+ *  Copyright (C) 1999-2025  The R Core Team
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -24,6 +24,7 @@
 
 #include <R_ext/RStartup.h>	/* The meat here */
 #ifdef _WIN32
+# include <R_ext/Boolean.h>     /* Rboolean */
 extern UImode  CharacterMode;
 extern Rboolean EmitEmbeddedUTF8;
 #endif