[tz] proposed changes for Win32 and a improved mktime() algorithm

[Paul Eggert]

Kees Dekker wrote:
> HP does not spend much time anymore to their compiler (because HPUX is almost dead?) and arguing with Microsoft
> about standards is certainly something that will never succeed.

The general rule is that if the platform isn't supported by its supplier any 
more then we don't need to support it either. HP says they will support HP-UX on 
Itanium until at least 2025, so it's still viable. However, some old HP-UX 
compilers are not supported by HP any more, so just saying "I need this for 
HP-UX" is not enough: the old unbundled C compiler is long obsolete, for 
example, and the PA-RISC platform is obsolete too.

And even if it's a viable compiler, if the compiler is merely generating 
false-alarm warnings then we typically do not bother "fixing" the code. Such 
"fixes" are often more trouble than they're worth. Fixing real bugs takes 
precedence over pacifying foolish compilers. You can ignore the false alarms 
with "grep -v".

Microsoft is another animal: they don't care about whether native MS-Windows 
conforms to POSIX, and we don't have the resources to maintain a port to their 
idiosyncratic system. Luckily, we don't need to, as POSIX-like environments such 
as Cygwin and WSL are readily available for MS-Windows, and though not perfect 
they're good enough.