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

src/compiler/linkage.h

Index: src/compiler/linkage.h
diff --git a/src/compiler/linkage.h b/src/compiler/linkage.h
index c1f37626550978733f8fc6443e04960b6ed3a2fb..fa34adb7c2e0926f9579eecaac86a22efe2f76ff 100644
--- a/src/compiler/linkage.h
+++ b/src/compiler/linkage.h
@@ -46,7 +46,7 @@ typedef Signature<LinkageLocation> LocationSignature;
 
 // Describes a call to various parts of the compiler. Every call has the notion
 // of a "target", which is the first input to the call.
-class CallDescriptor FINAL : public ZoneObject {
+class CallDescriptor final : public ZoneObject {
  public:
   // Describes the kind of this call, which determines the target.
   enum Kind {