Reverse e140122

- remove temporary fix for MemorySanitizer: setting p->u.array.count to 0 silenced a warning in JS_GetPropertyValue on a hacky test agains the length of fast_array object. This hack was removed by commit c363586.

Author: chqrlie

quickjs.c

@@ -14774,8 +14774,6 @@ static JSValue js_build_mapped_arguments(JSContext *ctx, int argc,
  if (JS_IsException(val))
  return val;
  p = JS_VALUE_GET_OBJ(val);
- p->u.array.u.values = NULL;
- p->u.array.count = 0;
 
  /* add the length field (cannot fail) */
  pr = add_property(ctx, p, JS_ATOM_length,