Circular-shift (rotate) operations for UInt (#1140)

* change static shift behavior to mod width when width is known
    * add dynamic shift
* basic tests that actually do something
    * MatchedRotateLeftAndRight based on the idea from @chick
    * BasicRotate rotate "b001" and compare with known values
* Fix check for KnownWidth(0|1) as suggested by @aswaterman
* Add dontTouch to UIntOps.io (other tests were also optimized out)

Co-authored-by: Chick Markley <chick@qrhino.com>
Co-authored-by: Andrew Waterman <andrew@sifive.com>