[Bug libstdc++/86015] Better handling of iterator distances

[joshua.r.marshall.1991 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86015

--- Comment #4 from Josh Marshall <joshua.r.marshall.1991 at gmail dot com> ---
These changes may make the stdlib implementation more robust, but there may be
an argument to stick to the more strict standard or tweak the standard.  Could
you link to the standard doc you're pulling from?  I'm not expert enough to
really figure if this report should be marked invalid or not.