Rearrange CLUSTER rules in gram.y.

This change moves the unparenthesized syntax for CLUSTER to the end
of the ClusterStmt rules in preparation for a follow-up commit that
will move this syntax to the "Compatibility" section of the CLUSTER
documentation.  The documentation for the CLUSTER syntaxes has also
been consolidated.

Suggested-by: Melanie Plageman
Discussion https://postgr.es/m/CAAKRu_bc5uHieG1976kGqJKxyWtyQt9yvktjsVX%2Bi7NOigDjOA%40mail.gmail.com

Author: nathan-bossart

doc/src/sgml/ref/cluster.sgml

@@ -21,9 +21,8 @@ PostgreSQL documentation
 
  <refsynopsisdiv>
 <synopsis>
-CLUSTER [VERBOSE] <replaceable class="parameter">table_name</replaceable> [ USING <replaceable class="parameter">index_name</replaceable> ]
-CLUSTER ( <replaceable class="parameter">option</replaceable> [, ...] ) <replaceable class="parameter">table_name</replaceable> [ USING <replaceable class="parameter">index_name</replaceable> ]
-CLUSTER [VERBOSE]
+CLUSTER [ ( <replaceable class="parameter">option</replaceable> [, ...] ) ] <replaceable class="parameter">table_name</replaceable> [ USING <replaceable class="parameter">index_name</replaceable> ]
+CLUSTER [ VERBOSE ] [ <replaceable class="parameter">table_name</replaceable> [ USING <replaceable class="parameter">index_name</replaceable> ] ]
 
 <phrase>where <replaceable class="parameter">option</replaceable> can be one of:</phrase>
 

src/backend/parser/gram.y

@@ -11553,33 +11553,32 @@ CreateConversionStmt:
 /*****************************************************************************
  *
  *		QUERY:
- *				CLUSTER [VERBOSE] <qualified_name> [ USING <index_name> ]
- *				CLUSTER [ (options) ] <qualified_name> [ USING <index_name> ]
- *				CLUSTER [VERBOSE]
+ *				CLUSTER (options) <qualified_name> [ USING <index_name> ]
+ *				CLUSTER [VERBOSE] [ <qualified_name> [ USING <index_name> ] ]
  *				CLUSTER [VERBOSE] <index_name> ON <qualified_name> (for pre-8.3)
  *
  *****************************************************************************/
 
 ClusterStmt:
-			CLUSTER opt_verbose qualified_name cluster_index_specification
+			CLUSTER '(' utility_option_list ')' qualified_name cluster_index_specification
 				{
 					ClusterStmt *n = makeNode(ClusterStmt);
 
-					n->relation = $3;
-					n->indexname = $4;
-					n->params = NIL;
-					if ($2)
-						n->params = lappend(n->params, makeDefElem("verbose", NULL, @2));
+					n->relation = $5;
+					n->indexname = $6;
+					n->params = $3;
 					$$ = (Node *) n;
 				}
-
-			| CLUSTER '(' utility_option_list ')' qualified_name cluster_index_specification
+			/* unparenthesized VERBOSE kept for pre-14 compatibility */
+			| CLUSTER opt_verbose qualified_name cluster_index_specification
 				{
 					ClusterStmt *n = makeNode(ClusterStmt);
 
-					n->relation = $5;
-					n->indexname = $6;
-					n->params = $3;
+					n->relation = $3;
+					n->indexname = $4;
+					n->params = NIL;
+					if ($2)
+						n->params = lappend(n->params, makeDefElem("verbose", NULL, @2));
 					$$ = (Node *) n;
 				}
 			| CLUSTER opt_verbose