Test nqp::codes with a code point bigger than an UTF16 code unit

Author: pmurias

t/nqp/059-nqpop.t

@@ -2,7 +2,7 @@
 
 # Test nqp::op pseudo-functions.
 
-plan(346);
+plan(347);
 
 ok( nqp::add_i(5,2) == 7, 'nqp::add_i');
 ok( nqp::sub_i(5,2) == 3, 'nqp::sub_i');
@@ -588,3 +588,4 @@ is(
   '0,1,2,3,a,b,c,5,6,7,8,9', 'nqp::splice test');
 
 is(nqp::codes('hello'), 5, 'nqp::codes with ascii');
+is(nqp::codes(nqp::chr(0x10426) ~ nqp::chr(0x10427)), 2, 'nqp::codes with chars bigger than a single code unit');