Fix a bunch of spelling mistakes :\

src/d8-readline.cc

 // Copyright 2008 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 17 matching lines @@
 
 #include <cstdio>  // NOLINT
 #include <readline/readline.h>
 #include <readline/history.h>
 
 
 #include "d8.h"
 
 
 // There are incompatibilities between different versions and different
-// implementations of readline.  This smoothes out one known incompatibility.
+// implementations of readline.  This smooths out one known incompatibility.
 #if RL_READLINE_VERSION >= 0x0500
 #define completion_matches rl_completion_matches
 #endif
 
 
 namespace v8 {
 
 
 class ReadLineEditor: public LineEditor {
  public:
@@ skipping 70 matching lines @@
     return strdup(*str);
   } else {
     current_completions.Dispose();
     current_completions.Clear();
     return NULL;
   }
 }
 
 
 }  // namespace v8