Revert "Don't allow utility or global targets in the LINKED expression."

This reverts commit 9712362b45.

Source/cmGeneratorExpressionEvaluator.cxx

@@ -759,14 +759,6 @@ private:
       {
       return std::string();
       }
-    if(target->GetType() >= cmTarget::UTILITY &&
-      target->GetType() != cmTarget::UNKNOWN_LIBRARY)
-      {
-      ::reportError(context, content->GetOriginalExpression(),
-                  "Target \"" + item
-                  + "\" is not an executable or library.");
-      return std::string();
-      }
     std::string propertyName = "INTERFACE_" + prop;
     const char *propContent = target->GetProperty(propertyName.c_str());
     if (!propContent)