C++: Always assign name to LookupScope

... except the global namespace and blocks

Change-Id: I0696b4997c28b5105a000bae2a9a4fa1a56eb6d3
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/libs/cplusplus/LookupContext.h

@@ -136,7 +136,7 @@ public:
 
     /// Create an empty LookupScope binding with the given \a parent.
     /// \internal
-    LookupScope *allocLookupScope(LookupScope *parent);
+    LookupScope *allocLookupScope(LookupScope *parent, const Name *name);
 
 protected:
     using SymbolVisitor::visit;