Fix cosmetic blemishes involving rd_createSubid.

Remove an obsolete comment from AtEOXact_cleanup().  Restore formatting
of a comment in struct RelationData, mangled by the pgindent run in
commit 9af4159fce.  Back-patch to 9.5 (all
supported versions), because another fix stacks on this.

src/backend/utils/cache/relcache.c

@@ -3031,10 +3031,7 @@ AtEOXact_cleanup(Relation relation, bool isCommit)
 	 *
 	 * During commit, reset the flag to zero, since we are now out of the
 	 * creating transaction.  During abort, simply delete the relcache entry
-	 * --- it isn't interesting any longer.  (NOTE: if we have forgotten the
-	 * new-ness of a new relation due to a forced cache flush, the entry will
-	 * get deleted anyway by shared-cache-inval processing of the aborted
-	 * pg_class insertion.)
+	 * --- it isn't interesting any longer.
 	 */
 	if (relation->rd_createSubid != InvalidSubTransactionId)
 	{

src/include/utils/rel.h

@@ -64,7 +64,7 @@ typedef struct RelationData
 								 * rd_replidindex) */
 	bool		rd_statvalid;	/* is rd_statlist valid? */
 
-	/*
+	/*----------
 	 * rd_createSubid is the ID of the highest subtransaction the rel has
 	 * survived into; or zero if the rel was not created in the current top
 	 * transaction.  This can be now be relied on, whereas previously it could
@@ -74,8 +74,13 @@ typedef struct RelationData
 	 * have forgotten changing it). rd_newRelfilenodeSubid can be forgotten
 	 * when a relation has multiple new relfilenodes within a single
 	 * transaction, with one of them occurring in a subsequently aborted
-	 * subtransaction, e.g. BEGIN; TRUNCATE t; SAVEPOINT save; TRUNCATE t;
-	 * ROLLBACK TO save; -- rd_newRelfilenode is now forgotten
+	 * subtransaction, e.g.
+	 *		BEGIN;
+	 *		TRUNCATE t;
+	 *		SAVEPOINT save;
+	 *		TRUNCATE t;
+	 *		ROLLBACK TO save;
+	 *		-- rd_newRelfilenodeSubid is now forgotten
 	 */
 	SubTransactionId rd_createSubid;	/* rel was created in current xact */
 	SubTransactionId rd_newRelfilenodeSubid;	/* new relfilenode assigned in