math.c: Get_Double
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49433 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
math.c: Get_Double
[Feature #10785]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49433 b2dd03c8-39d4-4d8f-98ff-823fe69b080e