In pg_upgrade, check that the binary and data directories are the same

major version.

Backpatch to 9.1.

Dan McGee

contrib/pg_upgrade/pg_upgrade.h

@@ -184,6 +184,7 @@ typedef struct
 	unsigned short port;		/* port number where postmaster is waiting */
 	uint32		major_version;	/* PG_VERSION of cluster */
 	char		major_version_str[64];	/* string PG_VERSION of cluster */
+	uint32		bin_version;	/* version returned from pg_ctl */
 	Oid			pg_database_oid;	/* OID of pg_database relation */
 	char	   *tablespace_suffix;		/* directory specification */
 } ClusterInfo;