configure.in: enable SSE2 on mingw
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45954 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
configure.in: enable SSE2 on mingw
[ruby-core:62095] [Bug #8358]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45954 b2dd03c8-39d4-4d8f-98ff-823fe69b080e