This makes no difference for the IA-64 C++ ABI nor for MSVC until MSVC
2019 16.6. But it does with 16.6, where the std::atomic constructor
becomes non-trivial, which makes QtPrivate::RefCount non-trivial, which
makes QLinkedListData non-trivial.
Before this change:
User code \ Qt MSVC <=16.5 MSVC >=16.6
MSVC <=16.5 works works
MSVC >=16.6 fails works
With this change, they should all work. The list of symbols exported
should not change either, so linking against a Qt compiled with MSVC
<=16.5 should continue to work.
[ChangeLog][MSVC] Fixed a compatibility issue found when linking code
compiled with version 16.6 to a Qt compiled with 16.5.
Fixes: QTBUG-81727
Change-Id: If79a52e476594446baccfffd15ee771397467f8b
Reviewed-by: Simon Hausmann <simon.hausmann@qt.io>
7af5619836