JDK-6886358 added layout support for Old Hangul however
it stops one short of the 0X11FF code point :-
changeset: 3171:1d4340015b85
user: srl
date: Mon Dec 06 16:10:01 2010 -0800
summary: 6886358: layout code update

+ else if (code < 0x1100) {
+ return false;
+ }
+ else if (code < 0x11ff) { // U+1100 - U+11FF Old Hangul
+ return true;
+ }