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/watchhandler.h

@@ -117,6 +117,9 @@ public:
     
     bool isEqual(const WatchData &other) const;
 
+    static QString msgNotInScope();
+    static QString shadowedName(const QString &name, int seen);
+
 public:
     QString iname;        // internal name sth like 'local.baz.public.a'
     QString exp;          // the expression
@@ -135,6 +138,7 @@ public:
     int generation;       // when updated?
     bool valueEnabled;    // value will be greyed out or not
     bool valueEditable;   // value will be editable
+    bool error;
 
 private: