A few small refactorings and typo fixes

src/hydrogen-mark-unreachable.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 19 matching lines @@
 
 #include "hydrogen.h"
 
 namespace v8 {
 namespace internal {
 
 
 class HMarkUnreachableBlocksPhase : public HPhase {
  public:
   explicit HMarkUnreachableBlocksPhase(HGraph* graph)
-      : HPhase("H_Mark unrechable blocks", graph) { }
+      : HPhase("H_Mark unreachable blocks", graph) { }
 
   void Run();
 
  private:
   void MarkUnreachableBlocks();
 
   DISALLOW_COPY_AND_ASSIGN(HMarkUnreachableBlocksPhase);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_MARK_UNREACHABLE_H_