Update V8 to r5091 as required by WebKit r63859.

Change-Id: I8e35d765e6f6c7f89eccff900e1cabe2d5dd6110
diff --git a/src/arm/assembler-arm.h b/src/arm/assembler-arm.h
index 6a4fb23..226fb87 100644
--- a/src/arm/assembler-arm.h
+++ b/src/arm/assembler-arm.h
@@ -130,6 +130,20 @@
   // Supporting d0 to d15, can be later extended to d31.
   bool is_valid() const  { return 0 <= code_ && code_ < 16; }
   bool is(DwVfpRegister reg) const  { return code_ == reg.code_; }
+  SwVfpRegister low() const  {
+    SwVfpRegister reg;
+    reg.code_ = code_ * 2;
+
+    ASSERT(reg.is_valid());
+    return reg;
+  }
+  SwVfpRegister high() const  {
+    SwVfpRegister reg;
+    reg.code_ = (code_ * 2) + 1;
+
+    ASSERT(reg.is_valid());
+    return reg;
+  }
   int code() const  {
     ASSERT(is_valid());
     return code_;
@@ -932,6 +946,12 @@
             const Condition cond = al);
 
   void vmov(const DwVfpRegister dst,
+            double imm,
+            const Condition cond = al);
+  void vmov(const SwVfpRegister dst,
+            const SwVfpRegister src,
+            const Condition cond = al);
+  void vmov(const DwVfpRegister dst,
             const DwVfpRegister src,
             const Condition cond = al);
   void vmov(const DwVfpRegister dst,