Stop debugging using lldb on Qt5/clang compiled app interrupts

Steps to reproduce:

• set up a kit using Qt5, clang, lldb engine
• create simple Qt Gui App (template from wizard)
• start debugging without setting breakpoint
• after inferior comes up push 'Stop' or trigger Menu 'Debugger' -> 'Stop Debugger' while inferior is in state running

Expected result:

• inferior is terminated, debugger stops

Current result:

• interrupt is triggered

Note: if you hit Stop while inferior is interrupted, stop works as expected.