No CDB debugger tooltip for variable in struct

1. Have a simple C++ program:

   #include <iostream>
   
   using namespace std;
   
   struct X{
       int x;
   
       void foo()
       {
           ++x;
       }
   };
   
   int main()
   {
       X x;
       x.foo();
       return 0;
   }
   

2. Set a breakpoint at "++x".
3. Run this in cdb.
4. When the execution stopped at the breakpoint, point your mouse at "++x".
   You'll only see a tooltip from the code model:
   

Before https://codereview.qt-project.org/99651/ you got a tooltip from the debugger:

Please bring back this tooltip.