Comment # 39 on bug 1185952 from Reinhard Max

I've seen this happen on all three versions of PostgreSQL that support LLVM
(11, 12 and 13), but only on s390x and only in about 4 out of 5 build runs
(within the short period over which I monitored it).

I think this should be handled in a separate bug report, because the bug at
hand got fixed and the reason for these new failures likely lies outside of the
PostgreSQL packages.