Debugger: Merge EngineSetup and InferiorSetup start phases

It was needed in the past to trigger e.g. gdbserver setup in
remote cases which is nowadays handled by separate RunWorkers.

Change-Id: I30bce071dab0779cce2e7abef7b31550d8539461
Reviewed-by: Christian Stenger <christian.stenger@qt.io>
Reviewed-by: David Schulz <david.schulz@qt.io>

src/plugins/debugger/gdb/gdbengine.h

@@ -405,7 +405,6 @@ private: ////////// General Interface //////////
     bool isTermEngine() const;
 
     void setupEngine() final;
-    void setupInferior() final;
     void runEngine() final;
     void shutdownEngine() final;
 
@@ -438,6 +437,7 @@ private: ////////// General Interface //////////
     QString coreFileName() const;
 
     QString mainFunction() const;
+    void setupInferior();
 
     Utils::QtcProcess m_gdbProc;
     OutputCollector m_outputCollector;