[Patch] Fix the narrow/widen problem in money_get::do_get

[Paolo Carlini]

Paolo Carlini wrote:

> Hi,
>
> this is the last missing bit of work, actually for a bug: the
> standard is pretty clear that ctype::widen must be used in do_get,
> not ctype::narrow (see 22.2.6.1.2, p4 and note 237).

Actually, we must also use ctype::widen (via _M_atoms made available by
the cache), in the parsing loop itself, and avoid ctype::is: forgot that!

Will update the patch, re-test and repost.

Paolo.