Ruby uses ANSI api to fork a process on Windows.
Japanese Shift_JIS and Traditional Chinese Big5 have 0x5c(backslash) problem
and these are incompatible with ASCII.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@5071 e93f8b46-1217-0410-a6f0-8f06a7374b81