Re: 'infinity'::Interval should be added

Hi,

On 2018-12-15 11:34:10 -0800, Andres Freund wrote:
> [1] We should optimize the computation using pg_add_s{32,64}_overflow,
>     the generated code after that change is *substantially* better (as
>     well as the original code much shorter, and correct).  And consider,
>     as mentioned further up, moving throwing the error out of line.

I don't have the focus to pursue this right now, so here's the changes
I'd made (for either somebody else to pick up, or as an archive for
myself).

Greetings,

Andres Freund