Debugger: Use the code model to detect unitialized variables.

This should save debugger round trips and crashes in the debugging
helpers.
Add respective option to debugging helper option page, defaulting to
true.On this occasion, make CDB detect shadowed variables correctly
and display them as "<shadowed n>" as does the Gdb engine by
reversing the direction in which
CdbSymbolGroupContext::populateINameIndexMap works.
Rubber-stamped-by: hjk <qtc-committer@nokia.com>

src/plugins/debugger/gdb/gdbengine.h

@@ -231,7 +231,7 @@ private:
     void setTokenBarrier();
 
     void updateAll();
-    void updateLocals();
+    void updateLocals(const QVariant &cookie = QVariant());
 
     void gdbInputAvailable(int channel, const QString &msg)
     { m_manager->showDebuggerInput(channel, msg); }
@@ -399,7 +399,9 @@ private:
         const WatchData &parent);
     void setWatchDataType(WatchData &data, const GdbMi &mi);
     void setWatchDataDisplayedType(WatchData &data, const GdbMi &mi);
-    void setLocals(const QList<GdbMi> &locals);
+    inline WatchData localVariable(const GdbMi &item,
+                                   const QStringList &uninitializedVariables,
+                                   QMap<QByteArray, int> *seen);
     void connectDebuggingHelperActions();
     void disconnectDebuggingHelperActions();
     AbstractGdbAdapter *createAdapter(const DebuggerStartParametersPtr &dp);