Unsigned types in Java now return bigger size signed types.

(Java doesn't support unsigned types).

ubyte/ushort return as int
uint returns as long
(all with correct masking)

ulong still returns as long, as before.

Tested: on Linux & Windows.
Bug 17521464

Change-Id: Id6bc8f38fc8c1a2f4e6733c6980dc6b6e322b452

tests/monster_test.fbs

@@ -24,6 +24,7 @@ struct Vec3 (force_align: 16) {
 table Stat {
   id:string;
   val:long;
+  count:ushort;
 }
 
 table Monster {