Test matching unicode astral digits

Author: pmurias

t/nqp/031-grammar.t

@@ -2,7 +2,7 @@
 
 # Test grammars and regexes
 
-plan(14);
+plan(15);
 
 grammar ABC {
     token TOP { ok ' ' <integer> }
@@ -67,3 +67,5 @@ is(Uniprop.parse('½')<unum>, '½', 'uniprop');
 is(Uniprop.parse('1')<unum>, '', "uniprop - doesn't match");
 is(NotUniprop.parse('12')<unum>, '1', 'negated uniprop - matches');
 is(NotUniprop.parse('½')<unum>, '', "negated uniprop - doesn't match");
+
+is(Uniprop.parse("\c[CUNEIFORM NUMERIC SIGN TWO ASH]")<unum>, "\c[CUNEIFORM NUMERIC SIGN TWO ASH]", 'astral unicode number');