Use 'new' in all the snapshot reallocation functions instead of realloc.

runtime/vm/object.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/cpu.h"
@@ skipping 5436 matching lines @@
     return -1;
   }
 
   void WriteIndex(intptr_t value) {
     stream_.WriteUnsigned(value + Token::kNumTokens);
   }
 
   static uint8_t* Reallocate(uint8_t* ptr,
                              intptr_t old_size,
                              intptr_t new_size) {
-    void* new_ptr = ::realloc(reinterpret_cast<void*>(ptr), new_size);
-    return reinterpret_cast<uint8_t*>(new_ptr);
+    return Utils::Realloc(ptr, old_size, new_size);
   }
 
   static const int kInitialTokenCount = 32;
   static const intptr_t kTableSize = 128;
 
   uint8_t* buffer_;
   WriteStream stream_;
   GrowableArray<intptr_t> ident_table_[kTableSize];
   GrowableArray<intptr_t> literal_table_[kTableSize];
   const GrowableObjectArray& token_objects_;
@@ skipping 7836 matching lines @@
                                     space);
   return reinterpret_cast<RawWeakProperty*>(raw);
 }
 
 
 const char* WeakProperty::ToCString() const {
   return "_WeakProperty";
 }
 
 }  // namespace dart