Fix existspos, pass test 59.

src/vm/js/bin/run_tests

@@ -1,5 +1,5 @@
 #!/bin/bash
 # 19 and 30 where moved out as they were parrot specific, 52,54 is missing, we can't pass 49 till we are bootstraped
 #echo 'No tests pass as we are in the early stages of a rewrite/refactor'
-prove -e  './nqp-js' t/nqp/{01..17}* t/nqp/{20,22,23,25,36,37,38,40,41,42,46,48,53,63,68,81,83}* t/js/getcomp-js.t
+prove -e  './nqp-js' t/nqp/{01..17}* t/nqp/{20,22,23,25,36,37,38,40,41,42,46,48,53,59,63,68,81,83}* t/js/getcomp-js.t
 #prove -e  './nqp-js' t/nqp/{01..29}*.t t/nqp/{31..48}* t/nqp/{50,51,53}* t/nqp/{55..81}* t/nqp/83* t/serialization/0{2,3}*.t

src/vm/js/nqp-runtime/core.js

@@ -162,7 +162,7 @@ exports.op.ishash = function(obj) {
 
 op.existspos = function(array, idx) {
   if (idx < 0) idx += array.length;
-  return boolish(array.hasOwnProperty(idx));
+  return array.hasOwnProperty(idx) ? 1 : 0;
 };
 
 op.create = function(obj) {

src/vm/js/nqp-runtime/runtime.js

@@ -50,6 +50,8 @@ exports.to_str = function(arg) {
     return arg.toString();
   } else if (typeof arg == 'string') {
     return arg;
+  } else if (arg.type_object_) {
+    return "";
   } else {
     console.log(arg);
     throw "Can't convert to str";