regroup subsequent const patterns

git-svn-id: http://haxe.googlecode.com/svn/trunk@5865 f16182fa-f095-11de-8f43-4547254af6c6
encode/decode Some None as { expr : null, pos : null } for switch default

git-svn-id: http://haxe.googlecode.com/svn/trunk@5866 f16182fa-f095-11de-8f43-4547254af6c6