fix doxygen brief in subzero header files

src/PNaClTranslator.h

 //===- subzero/src/PNaClTranslator.h - ICE from bitcode ---------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
-/// This file declares the PNaCl bitcode file to ICE, to machine code
-/// translator.
+/// \brief Declares the interface for translation from PNaCl bitcode files to
+/// ICE to machine code.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_PNACLTRANSLATOR_H
 #define SUBZERO_SRC_PNACLTRANSLATOR_H
 
 #include "IceTranslator.h"
 
 #include <string>
 
@@ skipping 20 matching lines @@
                  std::unique_ptr<llvm::MemoryObject> &&MemoryObject);
 
   /// Reads MemBuf, assuming it is the PNaCl bitcode contents of IRFilename.
   void translateBuffer(const std::string &IRFilename,
                        llvm::MemoryBuffer *MemBuf);
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_PNACLTRANSLATOR_H