mktime result may depend on previous calls

[Paul Eggert]

On 2023-01-18 23:10, Max Nikulin via Libc-alpha wrote:
> Has it been fixed recently?
> 
> https://www.gnu.org/software/libc/manual/html_node/Broken_002ddown-Time.html#index-mktime

Oops, looks like I was mistaken. I was thinking of the reference 
implementation of mktime in TZDB, not glibc mktime. The latter should be 
fixed to behave more like the former, and to use tm_gmtoff to 
disambiguate in the rare dicey cases.