Make some qHash and comparison operators overloads hidden friends

Restricts lookup scope more to necessary bits.

Change-Id: Ia42c95aaa70534843b7f6a90bfc56d2a1202c612
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

src/plugins/classview/classviewsymbolinformation.h

@@ -55,21 +55,15 @@ public:
 
     int iconTypeSortOrder() const;
 
+    friend auto qHash(const SymbolInformation &information) { return information.hash(); }
+
 private:
     const int m_iconType;
     const Utils::QHashValueType m_hash; // precalculated hash value - to speed up qHash
     const QString m_name;               // symbol name (e.g. SymbolInformation)
     const QString m_type;               // symbol type (e.g. (int char))
-
 };
 
-//! qHash overload for QHash/QSet
-inline auto qHash(const SymbolInformation &information)
-{
-    return information.hash();
-}
-
-
 } // namespace Internal
 } // namespace ClassView