[Lazarus] Qt/Qt5 users - need trunk testing

[zeljko]

Hi all,

For all Qt/Qt5 users of lazarus trunk: I've improved StretchMaskBlt() 
(BitBlt(), StretchBlt()) and fixed some issues #32137 and #32141 
(r62870).Usually those winapi functions are used by Canvas.CopyRect() 
and StretchDraw().

So, I need feedback if anything went wrong with such changes (linux, 
win32, mac).

Thanks,

zeljko