Clang: add globalFollowSymbol to RefactoringEngine

Allows to follow outside of current TU.

Change-Id: Ieea2fd72bfdf6d60a988b40efcf2f41c5a71d045
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/plugins/clangcodemodel/clangrefactoringengine.h

@@ -43,6 +43,12 @@ public:
     void globalRename(const CppTools::CursorInEditor &, CppTools::UsagesCallback &&,
                       const QString &) override {}
     void findUsages(const CppTools::CursorInEditor &, CppTools::UsagesCallback &&) const override {}
+    Link globalFollowSymbol(const CppTools::CursorInEditor &, const CPlusPlus::Snapshot &,
+                            const CPlusPlus::Document::Ptr &, CppTools::SymbolFinder *,
+                            bool) const override
+    {
+        return Link();
+    }
 };
 
 } // namespace ClangRefactoring