Avoid including any backend-only stuff in the zic utility program.

Per gripe from Zdenek Kotala, though not exactly his patch.

src/timezone/ialloc.c

@@ -3,10 +3,10 @@
  * 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/timezone/ialloc.c,v 1.8 2007/01/26 17:45:42 neilc Exp $
+ *	  $PostgreSQL: pgsql/src/timezone/ialloc.c,v 1.9 2007/10/26 13:30:10 tgl Exp $
  */
 
-#include "postgres.h"
+#include "postgres_fe.h"
 
 #include "private.h"
 

src/timezone/localtime.c

@@ -3,7 +3,7 @@
  * 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/timezone/localtime.c,v 1.17 2007/08/04 19:29:25 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/timezone/localtime.c,v 1.18 2007/10/26 13:30:10 tgl Exp $
  */
 
 /*
@@ -12,7 +12,8 @@
  * (guy@auspex.com).
  */
 
-#include "postgres.h"
+/* this file needs to build in both frontend and backend contexts */
+#include "c.h"
 
 #include <fcntl.h>
 

src/timezone/scheck.c

@@ -3,10 +3,10 @@
  * 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/timezone/scheck.c,v 1.7 2005/10/15 02:49:51 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/timezone/scheck.c,v 1.8 2007/10/26 13:30:10 tgl Exp $
  */
 
-#include "postgres.h"
+#include "postgres_fe.h"
 
 #include "private.h"
 

src/timezone/zic.c

@@ -3,10 +3,10 @@
  * 1996-06-05 by Arthur David Olson (arthur_david_olson@nih.gov).
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/timezone/zic.c,v 1.21 2007/02/01 19:10:30 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/timezone/zic.c,v 1.22 2007/10/26 13:30:10 tgl Exp $
  */
 
-#include "postgres.h"
+#include "postgres_fe.h"
 
 #ifdef HAVE_GETOPT_H
 #include <getopt.h>