iswdigit(3), iswxdigit(3): Don't limit to U007F

iswdigit(3), iswxdigit(3): Don't limit to U007F

We inherited a valid range of 00 - 127 for checking wide characters for
type digit or xdigit.

This is a mistake.  The relationship between digits (iswdigit) and
numbers (iswnumber, iswalnum) is that digits are a subset of numbers.
Digits are also a subset of xdigits (iswxdigit).  Digits are limited
to radix-10.  Numeric typess, on the other hand, include factions,
Roman Numerals, circled, etc.  It should cover the entire unicode
(UTF-8) range.

Unfortunately, DragonFly doesn't support the "number" type yet.  The
iswnumber and iswalnum just use the "digit" definition.  Note that
before this commit, they used full range for "digit" type while the
iswdigit() and iswdigits() themselves were limited.