Buildfarm has got the measles

A significant fraction of the buildfarm is showing this in HEAD:

***************
*** 375,382 ****
create table rewritemetoo1 of rewritetype;
create table rewritemetoo2 of rewritetype;
alter type rewritetype alter attribute a type text cascade;
- NOTICE: Table 'rewritemetoo1' is being rewritten (reason = 4)
NOTICE: Table 'rewritemetoo2' is being rewritten (reason = 4)
-- but this doesn't work
create table rewritemetoo3 (a rewritetype);
alter type rewritetype alter attribute a type varchar cascade;
--- 375,382 ----
create table rewritemetoo1 of rewritetype;
create table rewritemetoo2 of rewritetype;
alter type rewritetype alter attribute a type text cascade;
NOTICE: Table 'rewritemetoo2' is being rewritten (reason = 4)
+ NOTICE: Table 'rewritemetoo1' is being rewritten (reason = 4)
-- but this doesn't work
create table rewritemetoo3 (a rewritetype);
alter type rewritetype alter attribute a type varchar cascade;

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Evidently the order in which child tables are visited isn't too stable.
I'm inclined to think that that's fine and this regression test needs
reconsideration.

regards, tom lane