why does -vi- set the hi bit when expanding `%' and `#'?

[Guy Harris]

>As I understand it, we finally get to say goodbye to bit seven internal
>quoting with the System V, release 4 version of the shell.  It's
>possible that it's been eliminated in V.3.1 and later as well.

Heck, it was eliminated in the V.3 Bourne shell; that's why the V.3.1
(maybe the V.3, I don't remember) "vi" doesn't use the 8th-bit-quoting
hack anymore when running commands.  (It doesn't do any quoting.)