Allow ALTER TABLE name {OF type | NOT OF}.

This syntax allows a standalone table to be made into a typed table,
or a typed table to be made standalone.  This is possibly a mildly
useful feature in its own right, but the real motivation for this
change is that we need it to make pg_upgrade work with typed tables.
This doesn't actually fix that problem, but it's necessary
infrastructure.

Noah Misch

src/include/nodes/parsenodes.h

@@ -1219,6 +1219,8 @@ typedef enum AlterTableType
 	AT_DisableRule,				/* DISABLE RULE name */
 	AT_AddInherit,				/* INHERIT parent */
 	AT_DropInherit,				/* NO INHERIT parent */
+	AT_AddOf,					/* OF <type_name> */
+	AT_DropOf,					/* NOT OF */
 	AT_GenericOptions,			/* OPTIONS (...) */
 } AlterTableType;