[Development] MinGW with UCRT and Qt

[Björn Schäpers]

Hi,

I'm upgrading my build environment and switched my MinGW GCC from MSVCRT to 
UCRT. I'm not very far in compiling Qt, but get the following warnings:

qdatetime.cpp:2372:35: warning: 'tzname' is deprecated: Only provided for source 
compatibility; this variable might not always be accurate when linking to UCRT. 
[-Wdeprecated-declarations]
     return QString::fromLocal8Bit(tzname[isDst]);

It seems to me that we should use the #if defined(Q_CC_MSVC) path.

What would be the best way for that? I don't think you want a #if 
defined(Q_CC_MSVC) || defined(_UCRT), or do you? Are there any plans to adapt to 
UCRT MinGW?

Kind regards,
Björn.