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/macro-assembler.h b/src/macro-assembler.h
index 54cebca..2501f80 100644
--- a/src/macro-assembler.h
+++ b/src/macro-assembler.h
@@ -124,6 +124,74 @@
   bool old_has_frame_;
 };
 
+class FrameAndConstantPoolScope {
+ public:
+  FrameAndConstantPoolScope(MacroAssembler* masm, StackFrame::Type type)
+      : masm_(masm),
+        type_(type),
+        old_has_frame_(masm->has_frame()),
+        old_constant_pool_available_(FLAG_enable_ool_constant_pool &&
+                                     masm->is_ool_constant_pool_available()) {
+    masm->set_has_frame(true);
+    if (FLAG_enable_ool_constant_pool) {
+      masm->set_ool_constant_pool_available(true);
+    }
+    if (type_ != StackFrame::MANUAL && type_ != StackFrame::NONE) {
+      masm->EnterFrame(type, !old_constant_pool_available_);
+    }
+  }
+
+  ~FrameAndConstantPoolScope() {
+    masm_->LeaveFrame(type_);
+    masm_->set_has_frame(old_has_frame_);
+    if (FLAG_enable_ool_constant_pool) {
+      masm_->set_ool_constant_pool_available(old_constant_pool_available_);
+    }
+  }
+
+  // Normally we generate the leave-frame code when this object goes
+  // out of scope.  Sometimes we may need to generate the code somewhere else
+  // in addition.  Calling this will achieve that, but the object stays in
+  // scope, the MacroAssembler is still marked as being in a frame scope, and
+  // the code will be generated again when it goes out of scope.
+  void GenerateLeaveFrame() {
+    DCHECK(type_ != StackFrame::MANUAL && type_ != StackFrame::NONE);
+    masm_->LeaveFrame(type_);
+  }
+
+ private:
+  MacroAssembler* masm_;
+  StackFrame::Type type_;
+  bool old_has_frame_;
+  bool old_constant_pool_available_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(FrameAndConstantPoolScope);
+};
+
+// Class for scoping the the unavailability of constant pool access.
+class ConstantPoolUnavailableScope {
+ public:
+  explicit ConstantPoolUnavailableScope(MacroAssembler* masm)
+      : masm_(masm),
+        old_constant_pool_available_(FLAG_enable_ool_constant_pool &&
+                                     masm->is_ool_constant_pool_available()) {
+    if (FLAG_enable_ool_constant_pool) {
+      masm_->set_ool_constant_pool_available(false);
+    }
+  }
+  ~ConstantPoolUnavailableScope() {
+    if (FLAG_enable_ool_constant_pool) {
+      masm_->set_ool_constant_pool_available(old_constant_pool_available_);
+    }
+  }
+
+ private:
+  MacroAssembler* masm_;
+  int old_constant_pool_available_;
+
+  DISALLOW_IMPLICIT_CONSTRUCTORS(ConstantPoolUnavailableScope);
+};
+
 
 class AllowExternalCallThatCantCauseGC: public FrameScope {
  public: