[Bug bootstrap/107739] --enable-languages= duplicates yield odd error

[schwab--- via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107739

--- Comment #4 from Andreas Schwab <sch...@linux-m68k.org> ---
missing_languages=`echo "$missing_languages" |
                   sed -e ':loop' -e "s/,$language,/,/" -e 't loop'`