pg_upgrade failed if view contain natural left join condition

Steps to reproduce -

v9.6

postgres=# create table t(n int);
CREATE TABLE
postgres=# create table t1(a int);
CREATE TABLE
postgres=# create view ttt1 as SELECT e.n FROM t e NATURAL LEFT JOIN t1 d;
CREATE VIEW

v10 -

run pg_upgrade -

going to fail ,with this error -

"
pg_restore: creating TABLE "public.t"
pg_restore: creating TABLE "public.t1"
pg_restore: creating VIEW "public.ttt1"
pg_restore: [archiver (db)] Error while PROCESSING TOC:
pg_restore: [archiver (db)] Error from TOC entry 187; 1259 16390 VIEW 
ttt1 edb
pg_restore: [archiver (db)] could not execute query: ERROR:  syntax 
error at or near ")"
LINE 16:      LEFT JOIN "t1" "d");
                                 ^
     Command was:
-- For binary upgrade, must preserve pg_type oid
SELECT 
pg_catalog.binary_upgrade_set_next_pg_type_oid('16392'::pg_catalog.oid);


-- For binary upgrade, must preserve pg_type array oid
SELECT 
pg_catalog.binary_upgrade_set_next_array_pg_type_oid('16391'::pg_catalog.oid);


-- For binary upgrade, must preserve pg_class oids
SELECT 
pg_catalog.binary_upgrade_set_next_heap_pg_class_oid('16390'::pg_catalog.oid);

CREATE VIEW "ttt1" AS
  SELECT "e"."n"
    FROM ("t" "e"
      LEFT JOIN "t1" "d");

"
I think -this issue should be there in the older branches as well but 
not checked that.

-- 
regards,tushar
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