Move RelFileNumber declarations to common/relpath.h.

Previously, these were declared in postgres_ext.h, but they are not
needed nearly so widely as the OID declarations, so that doesn't
necessarily make sense. Also, because postgres_ext.h is included
before most of c.h has been processed, the previous location creates
some problems for a pending patch.

Patch by me, reviewed by Dilip Kumar.

Discussion: http://postgr.es/m/CA+TgmoYc8oevMqRokZQ4y_6aRn-7XQny1JBr5DyWR_jiFtONHw@mail.gmail.com

src/bin/pg_dump/pg_dump.c

@@ -55,6 +55,7 @@
 #include "catalog/pg_trigger_d.h"
 #include "catalog/pg_type_d.h"
 #include "common/connect.h"
+#include "common/relpath.h"
 #include "dumputils.h"
 #include "fe_utils/option_utils.h"
 #include "fe_utils/string_utils.h"

src/bin/pg_upgrade/pg_upgrade.h

@@ -10,6 +10,7 @@
 #include <sys/stat.h>
 #include <sys/time.h>
 
+#include "common/relpath.h"
 #include "libpq-fe.h"
 
 /* For now, pg_upgrade does not use common/logging.c; use our own pg_fatal */

src/include/catalog/binary_upgrade.h

@@ -14,6 +14,8 @@
 #ifndef BINARY_UPGRADE_H
 #define BINARY_UPGRADE_H
 
+#include "common/relpath.h"
+
 extern PGDLLIMPORT Oid binary_upgrade_next_pg_tablespace_oid;
 
 extern PGDLLIMPORT Oid binary_upgrade_next_pg_type_oid;

src/include/common/relpath.h

@@ -19,6 +19,13 @@
  */
 #include "catalog/catversion.h" /* pgrminclude ignore */
 
+/*
+ * RelFileNumber data type identifies the specific relation file name.
+ */
+typedef Oid RelFileNumber;
+#define InvalidRelFileNumber		((RelFileNumber) InvalidOid)
+#define RelFileNumberIsValid(relnumber) \
+				((bool) ((relnumber) != InvalidRelFileNumber))
 
 /*
  * Name of major-version-specific tablespace subdirectories

src/include/nodes/parsenodes.h

@@ -22,6 +22,7 @@
 #ifndef PARSENODES_H
 #define PARSENODES_H
 
+#include "common/relpath.h"
 #include "nodes/bitmapset.h"
 #include "nodes/lockoptions.h"
 #include "nodes/primnodes.h"

src/include/nodes/plannodes.h

@@ -16,6 +16,7 @@
 
 #include "access/sdir.h"
 #include "access/stratnum.h"
+#include "common/relpath.h"
 #include "lib/stringinfo.h"
 #include "nodes/bitmapset.h"
 #include "nodes/lockoptions.h"

src/include/postgres_ext.h

@@ -46,14 +46,6 @@ typedef unsigned int Oid;
 /* Define a signed 64-bit integer type for use in client API declarations. */
 typedef PG_INT64_TYPE pg_int64;
 
-/*
- * RelFileNumber data type identifies the specific relation file name.
- */
-typedef Oid RelFileNumber;
-#define InvalidRelFileNumber		((RelFileNumber) InvalidOid)
-#define RelFileNumberIsValid(relnumber) \
-				((bool) ((relnumber) != InvalidRelFileNumber))
-
 /*
  * Identifiers of error message fields.  Kept here to keep common
  * between frontend and backend, and also to export them to libpq

src/include/utils/relcache.h

@@ -15,6 +15,7 @@
 #define RELCACHE_H
 
 #include "access/tupdesc.h"
+#include "common/relpath.h"
 #include "nodes/bitmapset.h"