Restructure some header files a bit, in particular heapam.h, by removing some

unnecessary #include lines in it.  Also, move some tuple routine prototypes and
macros to htup.h, which allows removal of heapam.h inclusion from some .c
files.

For this to work, a new header file access/sysattr.h needed to be created,
initially containing attribute numbers of system columns, for pg_dump usage.

While at it, make contrib ltree, intarray and hstore header files more
consistent with our header style.

contrib/intarray/_int.h

@@ -1,18 +1,7 @@
 #ifndef ___INT_H__
 #define ___INT_H__
 
-#include "postgres.h"
-
-#include <float.h>
-
-#include "access/gist.h"
-#include "access/itup.h"
-#include "access/skey.h"
-#include "catalog/pg_type.h"
 #include "utils/array.h"
-#include "utils/builtins.h"
-#include "storage/bufpage.h"
-#include "lib/stringinfo.h"
 
 /* number ranges for compression */
 #define MAXNUMRANGE 100
@@ -173,4 +162,4 @@ if (ARRNELEMS(a) > 1)											\
 		qsort((void*)ARRPTR(a), ARRNELEMS(a),sizeof(int4),		\
 				(direction) ? compASC : compDESC )
 
-#endif
+#endif /* ___INT_H__ */

contrib/intarray/_int_bool.c

@@ -1,3 +1,7 @@
+#include "postgres.h"
+
+#include "utils/builtins.h"
+
 #include "_int.h"
 
 PG_FUNCTION_INFO_V1(bqarr_in);

contrib/intarray/_int_gin.c

@@ -1,3 +1,8 @@
+#include "postgres.h"
+
+#include "access/gist.h"
+#include "access/skey.h"
+
 #include "_int.h"
 
 PG_FUNCTION_INFO_V1(ginint4_queryextract);

contrib/intarray/_int_gist.c

@@ -1,3 +1,8 @@
+#include "postgres.h"
+
+#include "access/gist.h"
+#include "access/skey.h"
+
 #include "_int.h"
 
 #define GETENTRY(vec,pos) ((ArrayType *) DatumGetPointer((vec)->vector[(pos)].key))

contrib/intarray/_int_op.c

@@ -1,7 +1,10 @@
-#include "_int.h"
+#include "postgres.h"
 
 #include "lib/stringinfo.h"
 
+#include "_int.h"
+
+
 PG_MODULE_MAGIC;
 
 PG_FUNCTION_INFO_V1(_int_different);

contrib/intarray/_int_tool.c

@@ -1,3 +1,7 @@
+#include "postgres.h"
+
+#include "catalog/pg_type.h"
+
 #include "_int.h"
 
 

contrib/intarray/_intbig_gist.c

@@ -1,3 +1,8 @@
+#include "postgres.h"
+
+#include "access/gist.h"
+#include "access/skey.h"
+
 #include "_int.h"
 
 #define GETENTRY(vec,pos) ((GISTTYPE *) DatumGetPointer((vec)->vector[(pos)].key))