[tz] New leapseconds.awk doesn't work on macOS

[Deborah Goldsmith]

Hi,

I just noticed that starting with 2019c, leapseconds.awk is producing a damaged leapseconds file on macOS, e.g.:

> # All leap-seconds are Stationary (S) at the given UTC time.
> # The correction (+ or -) is made at the given time, so in the unlikely
> # event of a negative leap second, a line would look like this:
> # Leap  YEAR    MON     DAY     23:59:59        -       S
> # Typical lines look like this:
> # Leap  YEAR    MON     DAY     23:59:60        +       S
> 
> # POSIX timestamps for the data in this file:
> #updated -2208988800 (1900-01-01 00:00:00 UTC)
> #expires -2208988800 (1900-01-01 00:00:00 UTC)
> 

It turns out that having a regex in RS is a gawk feature and is not supported in Darwin awk. Commenting out the definition of RS in leapseconds.awk fixed the problem.

I don’t know how many customers of TZ will be using versions of awk that don’t support regexes in RS. I don’t know about FreeBSD, OpenBSD, etc.

Thanks,
Debbie