add .gitignore rules for Microsoft Visual C++
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50638 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
add .gitignore rules for Microsoft Visual C++
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@50638 b2dd03c8-39d4-4d8f-98ff-823fe69b080e