The following PIR:
.sub unicode:"\u7777"
   print "ok\n"
.end
Should print: "ok", but instead errors out with:
error:imcc:syntax error, unexpected USTRINGC, expecting IDENTIFIER or  
STRINGC or PARROT_OP
in file 'foo.pir' line 1
> .sub unicode:"\u7777"
>    print "ok\n"
> .end
This should be ok now as well as calling the sub, sub.t is passing 
again with r12863. More tests e.g. method calls are very welcome.
leo