Rename macro to RELKIND_HAS_STORAGE

The original name was an unfortunate choice.

Discussion: https://postgr.es/m/20181218.145600.172055615.horiguchi.kyotaro@lab.ntt.co.jp

src/backend/commands/copy.c

@@ -2405,7 +2405,7 @@ CopyFrom(CopyState cstate)
 	 *----------
 	 */
 	/* createSubid is creation check, newRelfilenodeSubid is truncation check */
-	if (RELKIND_CAN_HAVE_STORAGE(cstate->rel->rd_rel->relkind) &&
+	if (RELKIND_HAS_STORAGE(cstate->rel->rd_rel->relkind) &&
 		(cstate->rel->rd_createSubid != InvalidSubTransactionId ||
 		 cstate->rel->rd_newRelfilenodeSubid != InvalidSubTransactionId))
 	{

src/backend/commands/tablecmds.c

@@ -11003,7 +11003,7 @@ ATExecSetTableSpaceNoStorage(Relation rel, Oid newTableSpace)
 	 * Shouldn't be called on relations having storage; these are processed
 	 * in phase 3.
 	 */
-	Assert(!RELKIND_CAN_HAVE_STORAGE(rel->rd_rel->relkind));
+	Assert(!RELKIND_HAS_STORAGE(rel->rd_rel->relkind));
 
 	/* Can't allow a non-shared relation in pg_global */
 	if (newTableSpace == GLOBALTABLESPACE_OID)

src/include/catalog/pg_class.h

@@ -127,7 +127,7 @@ typedef FormData_pg_class *Form_pg_class;
  * relfilenode set to non-zero, but it can also be zero if the relation is
  * mapped.
  */
-#define RELKIND_CAN_HAVE_STORAGE(relkind) \
+#define RELKIND_HAS_STORAGE(relkind) \
 	((relkind) == RELKIND_RELATION || \
 	 (relkind) == RELKIND_INDEX || \
 	 (relkind) == RELKIND_SEQUENCE || \