Debugger: Dont use win64interrupt.exe in some case

If everything is built with 32 bitness there is no need
to call win64interrupt.exe

Task-number: QTCREATORBUG-7891

Change-Id: I1981b0dfd0ff08ff8acce0e5b81858b00f536ded
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Reviewed-by: hjk <qthjk@ovi.com>

src/plugins/debugger/cdb/cdbengine.h

@@ -265,6 +265,7 @@ private:
     bool m_operateByInstruction;
     bool m_notifyEngineShutdownOnTermination;
     bool m_hasDebuggee;
+    bool m_cdbIs64Bit;
     QTime m_logTime;
     mutable int m_elapsedLogTime;
     QByteArray m_extensionMessageBuffer;