win32.c: use PATH_MAX
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55270 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
win32.c: use PATH_MAX
PATH_MAX, except for MAX_PATH in get_special_folder for an API
limit.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@55270 b2dd03c8-39d4-4d8f-98ff-823fe69b080e