Mixed QML/C++ debugging does not work with CMake

1. Create a hybrid QML/C++ project (Qt Quick application), select CMake
2. Check that "Enable QML debugging and profiling" is set to "Leave at default"
3. Set a breakpoint in main.cpp before QApplication is constructed
4. Add a signal handler to main.qml:
   onWidthChanged: console.log("Hello World!")
5. Set breakpoint on this signal handler
6. Start debugging

The breakpoint on main.cpp should be hit right away and the breakpoint on the signal handler should be hit as soon as the window is resized horizontally.

Currently the QML breakpoint does not get hit.

Changing the "Enable QML debugging and profiling" to "Enable" makes this work.

With qmake, "Enable QML debugging and profiling" is automatically set to "Enable" and everything works out of the box here.