[modules] Support exporting a local variable under multiple export names.

src/ast/modules.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_MODULES_H_
 #define V8_AST_MODULES_H_
 
 #include "src/parsing/scanner.h"  // Only for Scanner::Location.
 #include "src/pending-compilation-error-handler.h"
 #include "src/zone/zone-containers.h"
@@ skipping 137 matching lines @@
     // We don't care if there's already an entry for this local name, as in that
     // case we will report an error when declaring the variable.
   }
 
   void AddSpecialImport(const Entry* entry, Zone* zone) {
     DCHECK_NULL(entry->export_name);
     DCHECK_LE(0, entry->module_request);
     special_imports_.Add(entry, zone);
   }
 
+  Handle<FixedArray> SerializeRegularExports(Isolate* isolate,
+                                             Zone* zone) const;
+  void DeserializeRegularExports(Isolate* isolate, AstValueFactory* avfactory,
+                                 Handle<FixedArray> data);
+
  private:
   // TODO(neis): Use STL datastructure instead of ZoneList?
   ZoneMap<const AstRawString*, int> module_requests_;
   ZoneList<const Entry*> special_exports_;
   ZoneList<const Entry*> special_imports_;
   ZoneMultimap<const AstRawString*, Entry*> regular_exports_;
   ZoneMap<const AstRawString*, const Entry*> regular_imports_;
 
   // If there are multiple export entries with the same export name, return the
   // last of them (in source order).  Otherwise return nullptr.
@@ skipping 23 matching lines @@
                   .insert(std::make_pair(specifier, module_requests_.size()))
                   .first;
     return it->second;
   }
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_AST_MODULES_H_