Remove the GLOBAL macro itself.

Now it's no longer used, we can get rid of it, and better still, get
rid of every #define PUTTY_DO_GLOBALS in the many source files that
previously had them.

windows/window.c

@@ -18,7 +18,6 @@
 #define COMPILE_MULTIMON_STUBS
 #endif
 
-#define PUTTY_DO_GLOBALS               /* actually _define_ globals */
 #include "putty.h"
 #include "terminal.h"
 #include "storage.h"

windows/winpgen.c

@@ -7,8 +7,6 @@
 #include <stdlib.h>
 #include <assert.h>
 
-#define PUTTY_DO_GLOBALS
-
 #include "putty.h"
 #include "ssh.h"
 #include "licence.h"

windows/winpgnt.c

@@ -9,8 +9,6 @@
 #include <assert.h>
 #include <tchar.h>
 
-#define PUTTY_DO_GLOBALS
-
 #include "putty.h"
 #include "ssh.h"
 #include "misc.h"

windows/winplink.c

@@ -7,7 +7,6 @@
 #include <assert.h>
 #include <stdarg.h>
 
-#define PUTTY_DO_GLOBALS               /* actually _define_ globals */
 #include "putty.h"
 #include "storage.h"
 #include "tree234.h"

windows/winstuff.h

@@ -157,19 +157,6 @@ struct FontSpec *fontspec_new(
     (p_##name = module ?                                \
      (t_##name) GetProcAddress(module, #name) : NULL)
 
-/*
- * Global variables. Most modules declare these `extern', but
- * window.c will do `#define PUTTY_DO_GLOBALS' before including this
- * module, and so will get them properly defined.
-*/
-#ifndef GLOBAL
-#ifdef PUTTY_DO_GLOBALS
-#define GLOBAL
-#else
-#define GLOBAL extern
-#endif
-#endif
-
 #define PUTTY_REG_POS "Software\\SimonTatham\\PuTTY"
 #define PUTTY_REG_PARENT "Software\\SimonTatham"
 #define PUTTY_REG_PARENT_CHILD "PuTTY"