Make zone_allocator actually usable.

src/zone-allocator.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_ALLOCATOR_H_
 #define V8_ZONE_ALLOCATOR_H_
 
+#include <limits>
+
 #include "zone.h"
 
 namespace v8 {
 namespace internal {
 
 template<typename T>
 class zone_allocator {
  public:
   typedef T* pointer;
   typedef const T* const_pointer;
   typedef T& reference;
   typedef const T& const_reference;
   typedef T value_type;
   typedef size_t size_type;
   typedef ptrdiff_t difference_type;
   template<class O> struct rebind {
     typedef zone_allocator<O> other;
   };
 
   explicit zone_allocator(Zone* zone) throw() : zone_(zone) {}
   explicit zone_allocator(const zone_allocator& other) throw()
       : zone_(other.zone_) {}
   template<typename U> zone_allocator(const zone_allocator<U>& other) throw()
       : zone_(other.zone_) {}
   template<typename U> friend class zone_allocator;
 
   pointer address(reference x) const {return &x;}
   const_pointer address(const_reference x) const {return &x;}
 
-  pointer allocate(size_type count, const void* hint = 0) {
-    size_t size = count * sizeof(value_type);
-    size = RoundUp(size, kPointerSize);
-    return static_cast<pointer>(zone_->New(size));
+  pointer allocate(size_type n, const void* hint = 0) {
+    return static_cast<pointer>(zone_->NewArray<value_type>(
+            static_cast<int>(n)));
   }
   void deallocate(pointer p, size_type) { /* noop for Zones */ }
 
   size_type max_size() const throw() {
-    size_type max = static_cast<size_type>(-1) / sizeof(T);
-    return (max > 0 ? max : 1);
+    return std::numeric_limits<int>::max() / sizeof(value_type);
   }
   void construct(pointer p, const T& val) {
     new(static_cast<void*>(p)) T(val);
   }
   void destroy(pointer p) { p->~T(); }
 
   bool operator==(zone_allocator const& other) {
     return zone_ == other.zone_;
   }
   bool operator!=(zone_allocator const& other) {
     return zone_ != other.zone_;
   }
 
  private:
   zone_allocator();
   Zone* zone_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ZONE_ALLOCATOR_H_