fixed i32 multiply overflow on JS (fixed issue #1532)

git-svn-id: http://haxe.googlecode.com/svn/trunk@6694 f16182fa-f095-11de-8f43-4547254af6c6
version update

git-svn-id: http://haxe.googlecode.com/svn/trunk@6695 f16182fa-f095-11de-8f43-4547254af6c6