I wrote:
> Looking around at other recent reports, it looks like we'll need to tweak
> the compiler version cutoffs a bit. I see for instance that spurfowl,
> with gcc (Ubuntu 5.4.0-6ubuntu1~16.04.11) 5.4.0 20160609, is whining:
> ...
> So maybe it'd better be __GNUC__ >= 6 not __GNUC__ >= 5. I think
> we can wait a little bit for more reports before messing with that,
> though.
Further reports show that gcc 6.x and 7.x also produce warnings,
so I moved the cutoff up to 8. Hopefully that's good enough.
We could write a configure test instead, but I'd just as soon not
expend configure cycles on this.
regards, tom lane