Allow OLD and NEW in multi-row VALUES within rules.

Now that we have LATERAL, it's fairly painless to allow this case, which
was left as a TODO in the original multi-row VALUES implementation.

src/include/nodes/parsenodes.h

@@ -758,7 +758,7 @@ typedef struct RangeTblEntry
 	 */
 	Alias	   *alias;			/* user-written alias clause, if any */
 	Alias	   *eref;			/* expanded reference names */
-	bool		lateral;		/* subquery or function is marked LATERAL? */
+	bool		lateral;		/* subquery, function, or values is LATERAL? */
 	bool		inh;			/* inheritance requested? */
 	bool		inFromCl;		/* present in FROM clause? */
 	AclMode		requiredPerms;	/* bitmask of required access permissions */

src/include/parser/parse_relation.h

@@ -67,6 +67,7 @@ extern RangeTblEntry *addRangeTableEntryForValues(ParseState *pstate,
 							List *exprs,
 							List *collations,
 							Alias *alias,
+							bool lateral,
 							bool inFromCl);
 extern RangeTblEntry *addRangeTableEntryForJoin(ParseState *pstate,
 						  List *colnames,