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
rewritetypealter 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
atype varchar cascade;
 
--- 375,382 ---- create table rewritemetoo1 of rewritetype; create table rewritemetoo2 of rewritetype; alter type
rewritetypealter 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