Version 3.5.6.

src/scopes.cc

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 379 matching lines @@
       variables_.Declare(this, name, Variable::VAR, true, Variable::NORMAL);
   params_.Add(var);
 }
 
 
 Variable* Scope::DeclareLocal(Handle<String> name, Variable::Mode mode) {
   ASSERT(!already_resolved());
   // This function handles VAR and CONST modes.  DYNAMIC variables are
   // introduces during variable allocation, INTERNAL variables are allocated
   // explicitly, and TEMPORARY variables are allocated via NewTemporary().
-  ASSERT(mode == Variable::VAR || mode == Variable::CONST);
+  ASSERT(mode == Variable::VAR ||
+         mode == Variable::CONST ||
+         mode == Variable::LET);
   ++num_var_or_const_;
   return variables_.Declare(this, name, mode, true, Variable::NORMAL);
 }
 
 
 Variable* Scope::DeclareGlobal(Handle<String> name) {
   ASSERT(is_global_scope());
   return variables_.Declare(this, name, Variable::DYNAMIC_GLOBAL, true,
                             Variable::NORMAL);
 }
@@ skipping 718 matching lines @@
   if (num_heap_slots_ == Context::MIN_CONTEXT_SLOTS &&
       !must_have_local_context) {
     num_heap_slots_ = 0;
   }
 
   // Allocation done.
   ASSERT(num_heap_slots_ == 0 || num_heap_slots_ >= Context::MIN_CONTEXT_SLOTS);
 }
 
 } }  // namespace v8::internal