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

[Deborah Goldsmith]

Thanks for the quick fix!

Debbie

> On Jan 11, 2020, at 8:30 AM, Paul Eggert <eggert at CS.UCLA.EDU> wrote:
> 
> On 1/10/20 7:32 PM, Deborah Goldsmith via tz wrote:
> 
>> It turns out that having a regex in RS is a gawk feature and is not supported in Darwin awk.
> 
> Thanks for reporting the problem. I installed the attached patch to fix this portability bug.
> <0001-Fix-leapseconds.awk-portability-bug.patch>