Replace OVERRIDE->override and FINAL->final since we now require C++11.

src/hydrogen-gvn.cc

Index: src/hydrogen-gvn.cc
diff --git a/src/hydrogen-gvn.cc b/src/hydrogen-gvn.cc
index 2ada8976ef18f8de33cbfbcf3bd456fa0dbae078..3836e32941467542c36e1a602a5fce06a04769bc 100644
--- a/src/hydrogen-gvn.cc
+++ b/src/hydrogen-gvn.cc
@@ -9,7 +9,7 @@
 namespace v8 {
 namespace internal {
 
-class HInstructionMap FINAL : public ZoneObject {
+class HInstructionMap final : public ZoneObject {
  public:
   HInstructionMap(Zone* zone, SideEffectsTracker* side_effects_tracker)
       : array_size_(0),
@@ -70,7 +70,7 @@ class HInstructionMap FINAL : public ZoneObject {
 };
 
 
-class HSideEffectMap FINAL BASE_EMBEDDED {
+class HSideEffectMap final BASE_EMBEDDED {
  public:
   HSideEffectMap();
   explicit HSideEffectMap(HSideEffectMap* other);