fix doxygen brief in subzero header files

src/IceCompiler.h

 //===- subzero/src/IceCompiler.h - Compiler driver --------------*- 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 driver for translating bitcode to native code.
+/// \brief Declares the driver for translating bitcode to native code.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICECOMPILER_H
 #define SUBZERO_SRC_ICECOMPILER_H
 
 #include "IceDefs.h"
 
 namespace llvm {
 class DataStreamer;
@@ skipping 13 matching lines @@
 
   /// Run the compiler with the given GlobalContext for compilation state. Upon
   /// error, the Context's error status will be set.
   void run(const ClFlagsExtra &ExtraFlags, GlobalContext &Ctx,
            std::unique_ptr<llvm::DataStreamer> &&InputStream);
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICECOMPILER_H