__INumField should always be double

git-svn-id: http://haxe.googlecode.com/svn/trunk@6414 f16182fa-f095-11de-8f43-4547254af6c6
Use hx::type_info

git-svn-id: http://haxe.googlecode.com/svn/trunk@6415 f16182fa-f095-11de-8f43-4547254af6c6