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}

---

FPIIM-449

Change-Id: I8c23c7bbb70772b4858fe8a47b64fa97ee0d1f8c
diff --git a/src/base/bits.cc b/src/base/bits.cc
index 6daee53..74d747f 100644
--- a/src/base/bits.cc
+++ b/src/base/bits.cc
@@ -3,6 +3,9 @@
 // found in the LICENSE file.
 
 #include "src/base/bits.h"
+
+#include <limits>
+
 #include "src/base/logging.h"
 
 namespace v8 {
@@ -20,6 +23,31 @@
   return value + 1;
 }
 
+
+int32_t SignedMulHigh32(int32_t lhs, int32_t rhs) {
+  int64_t const value = static_cast<int64_t>(lhs) * static_cast<int64_t>(rhs);
+  return bit_cast<int32_t, uint32_t>(bit_cast<uint64_t>(value) >> 32u);
+}
+
+
+int32_t SignedMulHighAndAdd32(int32_t lhs, int32_t rhs, int32_t acc) {
+  return bit_cast<int32_t>(bit_cast<uint32_t>(acc) +
+                           bit_cast<uint32_t>(SignedMulHigh32(lhs, rhs)));
+}
+
+
+int32_t SignedDiv32(int32_t lhs, int32_t rhs) {
+  if (rhs == 0) return 0;
+  if (rhs == -1) return -lhs;
+  return lhs / rhs;
+}
+
+
+int32_t SignedMod32(int32_t lhs, int32_t rhs) {
+  if (rhs == 0 || rhs == -1) return 0;
+  return lhs % rhs;
+}
+
 }  // namespace bits
 }  // namespace base
 }  // namespace v8