Restructure the key include files per recent pghackers discussion: there

are now separate files "postgres.h" and "postgres_fe.h", which are meant
to be the primary include files for backend .c files and frontend .c files
respectively.  By default, only include files meant for frontend use are
installed into the installation include directory.  There is a new make
target 'make install-all-headers' that adds the whole content of the
src/include tree to the installed fileset, for use by people who want to
develop server-side code without keeping the complete source tree on hand.
Cleaned up a whole lot of crufty and inconsistent header inclusions.

src/include/regex/regex.h

@@ -40,7 +40,6 @@
 #ifndef _REGEX_H_
 #define _REGEX_H_
 
-#include "postgres.h"
 #include <sys/types.h>
 #include "mb/pg_wchar.h"
 

src/include/regex/regex2.h

@@ -37,9 +37,7 @@
  *		@(#)regex2.h	8.4 (Berkeley) 3/20/94
  */
 
-#include "postgres.h"
-
-#include "limits.h"
+#include <limits.h>
 
 /*
  * First, the stuff that ends up in the outside-world include file

src/include/regex/utils.h

@@ -37,9 +37,7 @@
  *		@(#)utils.h		8.3 (Berkeley) 3/20/94
  */
 
-#include "postgres.h"
-
-#include "limits.h"
+#include <limits.h>
 
 /* utility definitions */
 #define DUPMAX			100000000		/* xxx is this right? */
@@ -50,6 +48,7 @@
 #else
 #define NC				(CHAR_MAX - CHAR_MIN + 1)
 #endif
+
 typedef unsigned char uch;
 
 /* switch off assertions (if not already off) if no REDEBUG */
@@ -58,8 +57,3 @@ typedef unsigned char uch;
 #define NDEBUG					/* no assertions please */
 #endif
 #endif
-
-/* for old systems with bcopy() but no memmove() */
-#if !defined(HAVE_MEMMOVE) && !defined(memmove)
-#define memmove(d, s, c)		bcopy(s, d, c)
-#endif