[modules] Split exports into regular and special, store regular ones in a multimap.

src/zone-containers.h

 // Copyright 2014 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_ZONE_CONTAINERS_H_
 #define V8_ZONE_CONTAINERS_H_
 
 #include <deque>
 #include <list>
 #include <map>
@@ skipping 104 matching lines @@
 template <typename K, typename V, typename Compare = std::less<K>>
 class ZoneMap
     : public std::map<K, V, Compare, zone_allocator<std::pair<const K, V>>> {
  public:
   // Constructs an empty map.
   explicit ZoneMap(Zone* zone)
       : std::map<K, V, Compare, zone_allocator<std::pair<const K, V>>>(
             Compare(), zone_allocator<std::pair<const K, V>>(zone)) {}
 };
 
+// A wrapper subclass for std::multimap to make it easy to construct one that
+// uses a zone allocator.
+template <typename K, typename V, typename Compare = std::less<K>>
+class ZoneMultimap
+    : public std::multimap<K, V, Compare,
+                           zone_allocator<std::pair<const K, V>>> {
+ public:
+  // Constructs an empty multimap.
+  explicit ZoneMultimap(Zone* zone)
+      : std::multimap<K, V, Compare, zone_allocator<std::pair<const K, V>>>(
+            Compare(), zone_allocator<std::pair<const K, V>>(zone)) {}
+};
 
 // Typedefs to shorten commonly used vectors.
 typedef ZoneVector<bool> BoolVector;
 typedef ZoneVector<int> IntVector;
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ZONE_CONTAINERS_H_