C++: Support ellipsis on variadic inheritance parsing

Change-Id: I571aefdb1f2aba88ba0c7710f16b6d8ad2e8f5a8
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/libs/3rdparty/cplusplus/Symbols.h

@@ -474,6 +474,9 @@ public:
     bool isVirtual() const;
     void setVirtual(bool isVirtual);
 
+    bool isVariadic() const;
+    void setVariadic(bool isVariadic);
+
     // Symbol's interface
     virtual FullySpecifiedType type() const;
     void setType(const FullySpecifiedType &type);
@@ -488,6 +491,7 @@ protected:
     virtual void visitSymbol0(SymbolVisitor *visitor);
 
 private:
+    bool _isVariadic;
     bool _isVirtual;
     FullySpecifiedType _type;
 };