Allow composite types in catalog bootstrap

When resolving types during catalog bootstrap, try to reload the pg_type
contents if a type is not found. That allows catalogs to contain
composite types, e.g. row types for other catalogs.

Author: Justin Pryzby
Reviewed-by: Dean Rasheed, Tomas Vondra
Discussion: https://postgr.es/m/ad7891d2-e90c-b446-9fe2-7419143847d7%40enterprisedb.com

Author: tvondra

src/backend/bootstrap/bootstrap.c

@@ -934,6 +934,29 @@ gettype(char *type)
 				return app->am_oid;
 			}
 		}
+
+		/*
+		 * The type wasn't known; reload the pg_type contents and check again
+		 * to handle composite types, added since last populating the list.
+		 */
+
+		list_free_deep(Typ);
+		Typ = NIL;
+		populate_typ_list();
+
+		/*
+		 * Calling gettype would result in infinite recursion for types missing
+		 * in pg_type, so just repeat the lookup.
+		 */
+		foreach (lc, Typ)
+		{
+			struct typmap *app = lfirst(lc);
+			if (strncmp(NameStr(app->am_typ.typname), type, NAMEDATALEN) == 0)
+			{
+				Ap = app;
+				return app->am_oid;
+			}
+		}
 	}
 	else
 	{