[m-rev.] for review: define <<u and >>u

[Julien Fischer]

On Tue, 6 Dec 2022, Zoltan Somogyi wrote:

> Add <<u and >>u to library/{int,uint}*.m ...
> 
> ... along with their unchecked equivalents. These differ from <<, >> and
> their unchecked equivalents in that they take the shift amount as a uint,
> instead of an int.

That's fine.  At some point compiler/const_prop.m and
compiler/simplify_goal_call.m will need to be updated to handlle
the new operations.

Julien.