ConvertToUnicode can't be used if the destination is a static buffer.
StandardName and DaylightName were invalid and timezone
redirection didn't work.
This regression was introduced with PR #3151
GetDynamicTimeZoneInformation, SetDynamicTimeZoneInformation and
GetTimeZoneInformationForYear are provided by the Windows SDK accordingly
with ethe MSDN cocumentation for SDK with versions above 7.1A.
Those functions are incorrectly included by the 7.1A SDK if _WIN32_WINNT
>= 0x0501 instead of _WIN32_WINNT >= 0x0600.
The issue arises when building with an XP compatible toolset (e.g.
v120_xp).
