[Development] Clazy results for Qt codebase

[Sergio Martins]

Hi,

KDAB is now running clazy over the Qt code base, you can check the 
results here: https://ci.kdab.com/~build/analysis/qt5/clazy.html

Next step is to figure out which sub-set we want to use in within 
qt-project, if we want to enforce any via CI, which ones we want to fix 
for Qt5 and which ones for Qt6.

I'll try to propose something soon, and probably focus on the checks 
that reveal real bugs, leaving the performance stuff for later.

For now I've just enabled almost all of them:

copyable-polymorphic
qstring-allocations
old-style-connect
returning-void-expression
virtual-calls-from-ctor
rule-of-three
connect-non-signal
qstring-arg
connect-not-normalized
qstring-insensitive-allocation
container-anti-pattern
qstring-ref
lambda-in-connect
qt-macros
mutable-container-key
qvariant-template-instantiation
qcolor-from-literal
strict-iterators
qdatetime-utc
temporary-iterator
qenums
unused-non-trivial-variable
qfileinfo-exists
writing-to-temporary
qgetenv
wrong-qglobalstatic
qmap-with-pointer-key
auto-unexpected-qstringbuilder
overridden-signal
child-event-qobject-cast
post-event
connect-3arg-lambda
qdeleteall
qhash-namespace
ctor-missing-parent-argument
qlatin1string-non-ascii
detaching-temporary
qproperty-without-notify
foreach
qstring-left
incorrect-emit
range-loop
inefficient-qlist-soft
returning-data-from-temporary
install-event-filter
rule-of-two-soft
non-pod-global-static
virtual-signal


Regards,
-- 
Sérgio Martins | sergio.martins at kdab.com | Senior Software Engineer
Klarälvdalens Datakonsult AB, a KDAB Group company
Tel: Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322)
KDAB - The Qt, C++ and OpenGL Experts