quotearg.c mbsinit

[Golubev I. N.]

version: bundled with bison-1.29
System: i586-pc-sco3.2v5.0.2

It obviously borrows code for counting length of multibyte sequence
from `mbswidth.c', and the following trouble of `mbswidth.c' also
applies to `quotearg.c'.

Some buggy libc's have `mbrtowc', but not `mbsinit' (violate Amendment
1 of ISO C90?).  It appears that this is because `mbstate_t' value is
never used by `mbrtowc' (`mbstate_t' is `char', just to shut
compiler), so the fix is to pretend that `mbsinit' always returns
true.

gettext-0.10.40 already implements such a fix, you need just to port
code from `mbswidth.c', `mbswidth.m4', `configure.in'.