[REG 3.6->4.0] Watches are severely broken

Dragging (or manually adding) a struct object to Watches just doesn't work.

It works if the watcher is already there when the application is executed, but adding it when the app is running (and interrupted) doesn't work.

struct Foo
{
    int a;
    int b;
};

int main()
{
    Foo foo;
    return 0; // break here, drag foo to Watches and expand
}

This works fine with 3.6