When printing an ObjC object, which is a pointer, lldb has handled it
the same way it treats any other pointer – printing only class name and
pointer address. The object is not expanded, its children are not shown.
This change updates `dwim-print` to print objc pointers by expanding (ie
dereferencing), with the assumption that it's what the user wants.
Note that this is currently possible using the `--ptr-depth`/`-P` flag.
With this change, when `dwim-print` prints root level objc objects, it's
the same effect as using `--ptr-depth 1`.