Limit recursion (and reduce total work) in CheckWidths (bp #1646) (#1663)

* Generalize pattern of ResolveKindsBenchmark

* Extend PassBenchmark to benchmark a particular Pass
* Add license note to file

(cherry picked from commit 88112433)

* Use recursive-then-iterative approach for check_width_e

* Avoid excessively deep recursion
* Avoid overhead of DFS for shallow expression trees
* Reduce work: skip expressions that cannot contain error-containing subtrees
* Review feedback: added commentary to explain new check_widths_e structure

(cherry picked from commit d7bd6d64

)

Co-authored-by: Albert Magyar <albert.magyar@gmail.com>