Scope analysis: DCHECK that we allocate rest_parameter_ only once.

src/ast/scopes.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/ast/scopes.h"
 
 #include <set>
 
 #include "src/accessors.h"
 #include "src/bootstrapper.h"
@@ skipping 1660 matching lines @@
 
 void DeclarationScope::AllocateLocals() {
   // For now, function_ must be allocated at the very end.  If it gets
   // allocated in the context, it must be the last slot in the context,
   // because of the current ScopeInfo implementation (see
   // ScopeInfo::ScopeInfo(FunctionScope* scope) constructor).
   if (function_ != nullptr) {
     AllocateNonParameterLocal(function_);
   }
 
-  if (rest_parameter_ != nullptr) {
-    AllocateNonParameterLocal(rest_parameter_);
-  }
+  DCHECK(rest_parameter_ == nullptr || !rest_parameter_->IsUnallocated());
 
   if (new_target_ != nullptr && !MustAllocate(new_target_)) {
     new_target_ = nullptr;
   }
 
   if (this_function_ != nullptr && !MustAllocate(this_function_)) {
     this_function_ = nullptr;
   }
 }
 
@@ skipping 75 matching lines @@
       function != nullptr && function->IsContextSlot();
   return num_heap_slots() - Context::MIN_CONTEXT_SLOTS - num_global_slots() -
          (is_function_var_in_context ? 1 : 0);
 }
 
 
 int Scope::ContextGlobalCount() const { return num_global_slots(); }
 
 }  // namespace internal
 }  // namespace v8