Sujit Muduli

Results 2 issues of Sujit Muduli

We were testing out some of the **ulib** ocaml library function for strings generated from its Fstar implementation. For [length](https://github.com/FStarLang/FStar/blob/60844c6deb4501d4808908a434f113a7800a722f/ulib/FStar.String.fsti#L55) and [concat](https://github.com/FStarLang/FStar/blob/60844c6deb4501d4808908a434f113a7800a722f/ulib/FStar.String.fsti#L76)(^) functions, we found a test input which violates...

This change implements a type visitor for computing the bitsize of a given type. It resolves #970