Update to current version of the SpiderMonkey shell, adjust for thedifferent handling of for loops…

scripts/abprewrite.js

 // This script rewrites AST to be compatible with JavaScript 1.5 and decompiles
 // the modified tree then
 
 include("../scripts/astDecompile.js");
 include("../utils/beautify.js");
 
 let headerPrinted = false;
 
 // See https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API for
 // AST structure.
@@ skipping 337 matching lines @@
       body: block
     };
   }
 
   // Make sure that the loop body is always wrapped in a block
   ast.body = ensureBlock(ast.body);
 
   return ast;
 }
 
+function modifyLetStatement(ast)
+{
+  if (ast.body.type == "ForStatement" && ast.body.init == null)
+  {
+    // Convert back "for" loops written as "let" statements:
+    // let (foo = 0) for (; foo < bar; ++foo)
+    // {
+    //   ...
+    // }
+    //
+    // Change into:
+    // for (let foo = 0; foo < bar; ++foo)
+    // {
+    //   ...
+    // }
+    ast.body.init = {
+      type: "VariableDeclaration",
+      declarations: [],
+      kind: "let"
+    };
+    for (let i = 0; i < ast.head.length; i++)
+    {
+      ast.head[i].type = "VariableDeclarator";
+      ast.body.init.declarations.push(ast.head[i]);
+    }
+    return modifyForStatement(ast.body);
+  }
+
+  return ast;
+}
+
 function modifyFunctionExpression(ast)
 {
   if (ast.expression)
   {
     // Convert expression closures:
     // function() foo;
     //
     // Change into:
     // function()
     // {
@@ skipping 141 matching lines @@
     let code = 'require.scopes["' + options.filename + '"] = (function() {\n' +
                'var exports = {};\n' +
                decompileAST(ast) +
                'return exports;\n' +
                '})();\n';
     _print(js_beautify(code, options));
   }
   else
     _print(js_beautify(decompileAST(ast), options));
 }