qt_safe_sendmsg/sendto call may cause infinite loop

I am listing this as an iOS bug and a bug specific to sendmsg and sendto, because that is where I've seen this reproducing. However, from looking at the code it seems to me this could be an issue in any platform and in any of these `qt_safe_*` function on https://codebrowser.dev/qt5/qtbase/src/network/socket/qnet_unix_p.h.html#_ZL15qt_safe_sendmsgiPK6msghdri. Due to the way EINTR_LOOP is defined.

The infinite loop is caused by the sendmsg/sendto calls failing continually until and results in a crash in the application.