This algorithm doesn't handle the case when a path, fully-ellipsised, is
still longer than the specified maxWidth.

For example, for a path with 21 segments, the string the util would
build is …/…/…/…/…/…/…/…/…/…/…/…/…/…/…/…/…/…/…/…/…, which is 41
characters long, so the `while` condition is never false, leading to the
infinite loop.

This adds a condition to handle that case, returning a truncated string
that never exceeds the maxWidth, no matter how deep the path is.