*Not* using /permissive- exposes Qt and client apps to interesting
bugs and/or build failures, (e.g. QTBUG-87225, or
19b5520abf). We demand strict
conformance by any other compiler, it's time to demand it from
MSVC too.
The Windows headers themselves are clean starting from the
Windows Fall Creators SDK (10.0.16299.0), and moreover Qt 6 will
drop WinRT; therefore, the comment in the mkspecs does not apply
any more.
Since /permissive- implies /Zc:referenceBinding, drop that
option. The other implied options are set on MSVC < 2017,
but I leave them in to avoid tinkering with the fragile lists
of C/C++ flags.
Rename the CMake internal helper function to better describe
what it does.
Fixes: QTBUG-85633
Fixes: QTBUG-85637
Fixes: QTBUG-85635
Fixes: QTBUG-88244
Change-Id: Ie03fddb61aa066fdc14b7231c22e7108b4a02fbb
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>
8780fbb2eb