Fix copyfuncs/equalfuncs support for VacuumStmt.

Commit 6776142a failed to do this,
and the buildfarm broke.

Patch by me, per advice from Tom Lane and Michael Paquier.

Discussion: http://postgr.es/m/13988.1552960403@sss.pgh.pa.us

src/backend/nodes/copyfuncs.c

@@ -3852,8 +3852,9 @@ _copyVacuumStmt(const VacuumStmt *from)
 {
 	VacuumStmt *newnode = makeNode(VacuumStmt);
 
-	COPY_SCALAR_FIELD(options);
+	COPY_NODE_FIELD(options);
 	COPY_NODE_FIELD(rels);
+	COPY_SCALAR_FIELD(is_vacuumcmd);
 
 	return newnode;
 }

src/backend/nodes/equalfuncs.c

@@ -1671,8 +1671,9 @@ _equalDropdbStmt(const DropdbStmt *a, const DropdbStmt *b)
 static bool
 _equalVacuumStmt(const VacuumStmt *a, const VacuumStmt *b)
 {
-	COMPARE_SCALAR_FIELD(options);
+	COMPARE_NODE_FIELD(options);
 	COMPARE_NODE_FIELD(rels);
+	COMPARE_SCALAR_FIELD(is_vacuumcmd);
 
 	return true;
 }