Frog: Fix parsing of hex literals with >31 bits

frog/frogsh

 #!/usr/bin/env node
 //  ********** Library dart:core **************
 //  ********** Natives dart:core **************
 /**
  * Generates a dynamic call stub for a function.
  * Our goal is to create a stub method like this on-the-fly:
  *   function($0, $1, capture) { this($0, $1, true, capture); }
  *
  * This stub then replaces the dynamic one on Function, with one that is
  * specialized for that particular function, taking into account its default
@@ skipping 19856 matching lines @@
   else {
     return -1;
   }
 }
 lang_Parser.parseHex = function(hex) {
   var result = 0;
   for (var i = 0;
    i < hex.length; i++) {
     var digit = lang_Parser._hexDigit(hex.charCodeAt(i));
     $assert($ne(digit, -1), "digit != -1", "parser.dart", 1339, 14);
-    result = (result << 4) + $assert_num(digit);
+    result = (result * 16) + $assert_num(digit);
   }
   return $assert_num(result);
 }
 lang_Parser.prototype.finishNewExpression = function(start, isConst) {
   var type = this.type(0);
   var name = null;
   if ($notnull_bool(this._maybeEat(14/*TokenKind.DOT*/))) {
     name = this.identifier();
   }
   var args = this.arguments();
@@ skipping 4267 matching lines @@
       NATIVE,
       NEGATE,
       OPERATOR,
       SET,
       SOURCE,
       STATIC,
       TYPEDEF ]*/;
 var $globals = {};
 $static_init();
 main();