Upgrade V8 to 5.1.281.57  DO NOT MERGE

FPIIM-449

Change-Id: Id981b686b4d587ac31697662eb98bb34be42ad90
(cherry picked from commit 3b9bc31999c9787eb726ecdbfd5796bfdec32a18)
diff --git a/src/x64/assembler-x64.h b/src/x64/assembler-x64.h
index 2847ff2..e48f358 100644
--- a/src/x64/assembler-x64.h
+++ b/src/x64/assembler-x64.h
@@ -699,8 +699,10 @@
   void movp(Register dst, void* ptr, RelocInfo::Mode rmode);
 
   // Loads a 64-bit immediate into a register.
-  void movq(Register dst, int64_t value);
-  void movq(Register dst, uint64_t value);
+  void movq(Register dst, int64_t value,
+            RelocInfo::Mode rmode = RelocInfo::NONE64);
+  void movq(Register dst, uint64_t value,
+            RelocInfo::Mode rmode = RelocInfo::NONE64);
 
   void movsxbl(Register dst, Register src);
   void movsxbl(Register dst, const Operand& src);
@@ -771,6 +773,10 @@
     arithmetic_op_16(0x39, src, dst);
   }
 
+  void testb(Register reg, const Operand& op) { testb(op, reg); }
+
+  void testw(Register reg, const Operand& op) { testw(op, reg); }
+
   void andb(Register dst, Immediate src) {
     immediate_arithmetic_op_8(0x4, dst, src);
   }
@@ -846,6 +852,11 @@
   void testb(const Operand& op, Immediate mask);
   void testb(const Operand& op, Register reg);
 
+  void testw(Register dst, Register src);
+  void testw(Register reg, Immediate mask);
+  void testw(const Operand& op, Immediate mask);
+  void testw(const Operand& op, Register reg);
+
   // Bit operations.
   void bt(const Operand& dst, Register src);
   void bts(const Operand& dst, Register src);
@@ -1695,7 +1706,9 @@
   void dp(uintptr_t data) { dq(data); }
   void dq(Label* label);
 
-  PositionsRecorder* positions_recorder() { return &positions_recorder_; }
+  AssemblerPositionsRecorder* positions_recorder() {
+    return &positions_recorder_;
+  }
 
   // Check if there is less than kGap bytes available in the buffer.
   // If this is the case, we need to grow the buffer before emitting
@@ -2178,8 +2191,8 @@
 
   List< Handle<Code> > code_targets_;
 
-  PositionsRecorder positions_recorder_;
-  friend class PositionsRecorder;
+  AssemblerPositionsRecorder positions_recorder_;
+  friend class AssemblerPositionsRecorder;
 };