Potential crash when using debugger with `debugger.stopAtEntryPoint` set to false

[xusheng6]

As mentioned in https://github.com/Vector35/debugger/issues/548, when we set debugger.stopAtEntryPoint to false, the debugger binary view is not created until the target stops for the very first time. However, certain parts of the debugger is written with the assumption that the debugger binary view always exists. So this combination could lead to various crashes