Only conditionally add inner scope when deserializing

src/ast/scopes.h

 // 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.
 
 #ifndef V8_AST_SCOPES_H_
 #define V8_AST_SCOPES_H_
 
 #include "src/ast/ast.h"
 #include "src/base/hashmap.h"
 #include "src/globals.h"
@@ skipping 604 matching lines @@
 
   // Construct a scope based on the scope info.
   Scope(Zone* zone, Scope* inner_scope, ScopeType type,
         Handle<ScopeInfo> scope_info);
 
   // Construct a catch scope with a binding for the name.
   Scope(Zone* zone, Scope* inner_scope,
         const AstRawString* catch_variable_name);
 
   void AddInnerScope(Scope* inner_scope) {
-    if (inner_scope != nullptr) {
-      inner_scope->sibling_ = inner_scope_;
-      inner_scope_ = inner_scope;
-      inner_scope->outer_scope_ = this;
-    }
+    inner_scope->sibling_ = inner_scope_;
+    inner_scope_ = inner_scope;
+    inner_scope->outer_scope_ = this;
   }
 
   void RemoveInnerScope(Scope* inner_scope) {
     DCHECK_NOT_NULL(inner_scope);
     if (inner_scope == inner_scope_) {
       inner_scope_ = inner_scope_->sibling_;
       return;
     }
     for (Scope* scope = inner_scope_; scope != nullptr;
          scope = scope->sibling_) {
@@ skipping 252 matching lines @@
   // Convenience variable; Subclass constructor only
   Variable* this_function_;
   // Module descriptor; module scopes only.
   ModuleDescriptor* module_descriptor_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_SCOPES_H_