dir.c: long path name on Windows
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49537 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
dir.c: long path name on Windows
no tilde is there. [ruby-core:68011] [Bug #10819]
character, check if exists before call it. cf. [Bug #8597]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49537 b2dd03c8-39d4-4d8f-98ff-823fe69b080e