[d8] Do not try to verify zero-ness of failed virtual memory allocation.

BUG=chromium:667603
R=clemensh@chromium.org

Review-Url: https://codereview.chromium.org/2519363002
Cr-Commit-Position: refs/heads/master@{#41174}

src/d8.cc

@@ -76,10 +76,13 @@ class ShellArrayBufferAllocator : public v8::ArrayBuffer::Allocator {
     if (RoundToPageSize(&length)) {
       void* data = VirtualMemoryAllocate(length);
 #if DEBUG
-      // In debug mode, check the memory is zero-initialized.
-      uint8_t* ptr = reinterpret_cast<uint8_t*>(data);
-      for (size_t i = 0; i < length; i++) {
-        DCHECK_EQ(0, ptr[i]);
+      if (data) {
+        // In debug mode, check the memory is zero-initialized.
+        size_t limit = length / sizeof(uint64_t);
+        uint64_t* ptr = reinterpret_cast<uint64_t*>(data);
+        for (size_t i = 0; i < limit; i++) {
+          DCHECK_EQ(0u, ptr[i]);
+        }
       }
 #endif
       return data;

test/mjsunit/regress/regress-667603.js

+// Copyright 2016 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.
+
+try {
+  var v65 = new ArrayBuffer(2147483647);
+} catch(e) {
+  assertTrue(e instanceof RangeError);
+}