Use V8_FINAL and V8_OVERRIDE in various places, fixing bugs revealed by them.

src/mips/lithium-codegen-mips.h

Index: src/mips/lithium-codegen-mips.h
diff --git a/src/mips/lithium-codegen-mips.h b/src/mips/lithium-codegen-mips.h
index 550dfbbd303194c2c202b5bf500437d25a650b49..13b58040bd660b444b054a6ff5168c9c53cf5275 100644
--- a/src/mips/lithium-codegen-mips.h
+++ b/src/mips/lithium-codegen-mips.h
@@ -42,7 +42,7 @@ namespace internal {
 class LDeferredCode;
 class SafepointGenerator;
 
-class LCodeGen FINAL  BASE_EMBEDDED {
+class LCodeGen V8_FINAL  BASE_EMBEDDED {
  public:
   LCodeGen(LChunk* chunk, MacroAssembler* assembler, CompilationInfo* info)
       : zone_(info->zone()),
@@ -441,7 +441,7 @@ class LCodeGen FINAL  BASE_EMBEDDED {
 
   int old_position_;
 
-  class PushSafepointRegistersScope FINAL  BASE_EMBEDDED {
+  class PushSafepointRegistersScope V8_FINAL  BASE_EMBEDDED {
    public:
     PushSafepointRegistersScope(LCodeGen* codegen,
                                 Safepoint::Kind kind)