Update V8 to version 4.1.0.21

This is a cherry-pick of all commits up to and including the
4.1.0.21 cherry-pick in Chromium.

Original commit message:

Version 4.1.0.21 (cherry-pick)

Merged 206e9136bde0f2b5ae8cb77afbb1e7833e5bd412

Unlink pages from the space page list after evacuation.

BUG=430201
LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/953813002

Cr-Commit-Position: refs/branch-heads/4.1@{#22}
Cr-Branched-From: 2e08d2a7aa9d65d269d8c57aba82eb38a8cb0a18-refs/heads/candidates@{#25353}

---

Change-Id: I8c23c7bbb70772b4858fe8a47b64fa97ee0d1f8c

1 files changed, 58 insertions, 0 deletions

diff --git a/src/bit-vector.cc b/src/bit-vector.cc
new file mode 100644
index 00000000..198b2427
--- /dev/null
+++ b/src/bit-vector.cc
@@ -0,0 +1,58 @@
+// Copyright 2010 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.
+
+#include "src/bit-vector.h"
+
+#include "src/base/bits.h"
+#include "src/scopes.h"
+
+namespace v8 {
+namespace internal {
+
+#ifdef DEBUG
+void BitVector::Print() {
+  bool first = true;
+  PrintF("{");
+  for (int i = 0; i < length(); i++) {
+    if (Contains(i)) {
+      if (!first) PrintF(",");
+      first = false;
+      PrintF("%d", i);
+    }
+  }
+  PrintF("}");
+}
+#endif
+
+
+void BitVector::Iterator::Advance() {
+  current_++;
+  uintptr_t val = current_value_;
+  while (val == 0) {
+    current_index_++;
+    if (Done()) return;
+    val = target_->data_[current_index_];
+    current_ = current_index_ << kDataBitShift;
+  }
+  val = SkipZeroBytes(val);
+  val = SkipZeroBits(val);
+  current_value_ = val >> 1;
+}
+
+
+int BitVector::Count() const {
+  int count = 0;
+  for (int i = 0; i < data_length_; i++) {
+    uintptr_t data = data_[i];
+    if (sizeof(data) == 8) {
+      count += base::bits::CountPopulation64(data);
+    } else {
+      count += base::bits::CountPopulation32(static_cast<uint32_t>(data));
+    }
+  }
+  return count;
+}
+
+}  // namespace internal
+}  // namespace v8