I wrote:
> That is, even if configure finds an int128 type, we'll only use it if
> it fits or can be made to fit into our system-wide MAXALIGN assumption.
> ...
> Barring objections, I'll get on with making this happen.
I've pushed fixes along this line into the affected branches.
Anybody who's looking for a quick-hack fix might be better advised
to use the short patch I posted upthread, though.
regards, tom lane