Completion for constructors used on initialization

Deals with cases like "QString s(", but for the moment doesn't handle
yet "QString const s(".

Done with Roberto Raggi.

(cherry picked from commit fca3ec1f32)

src/plugins/cpptools/cppcodecompletion.h

@@ -103,6 +103,8 @@ private:
                        const CPlusPlus::LookupContext &context,
                        bool staticLookup = true);
 
+    bool completeConstructors(CPlusPlus::Class *klass);
+
     bool completeQtMethod(CPlusPlus::FullySpecifiedType exprTy,
                           const QList<CPlusPlus::TypeOfExpression::Result> &,
                           const CPlusPlus::LookupContext &context,
@@ -118,7 +120,7 @@ private:
                       const CPlusPlus::LookupContext &context)
     { return completeQtMethod(exprTy, results, context, false); }
 
-    static int findStartOfName(const TextEditor::ITextEditor *editor);
+    int findStartOfName(int pos = -1) const;
 
     QList<TextEditor::CompletionItem> m_completions;