C++: Store template typename argument declarator type

Differentiate class from typename. Used by a follow-up commit for pretty
printing, preserving the original declarator.

Change-Id: I496505f5062abb69d5552e5422db256d49d164c4
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

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

@@ -187,6 +187,8 @@ public:
     virtual ~TypenameArgument();
 
     void setType(const FullySpecifiedType &type);
+    void setClassDeclarator(bool isClassDecl) { _isClassDeclarator = isClassDecl; }
+    bool isClassDeclarator() const { return _isClassDeclarator; }
 
     // Symbol's interface
     virtual FullySpecifiedType type() const;
@@ -202,6 +204,7 @@ protected:
 
 private:
     FullySpecifiedType _type;
+    bool _isClassDeclarator;
 };
 
 class CPLUSPLUS_EXPORT Block: public Scope