fix doxygen brief in subzero header files

src/IceAssembler.h

 //===- subzero/src/IceAssembler.h - Integrated assembler --------*- C++ -*-===//
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 //
 // Modified by the Subzero authors.
 //
 //===----------------------------------------------------------------------===//
 //
 //                        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 Assembler base class. Instructions are assembled by
-/// architecture-specific assemblers that derive from this base class. This base
-/// class manages buffers and fixups for emitting code, etc.
+/// \brief Declares the Assembler base class.
+///
+/// Instructions are assembled by architecture-specific assemblers that derive
+/// from this base class. This base class manages buffers and fixups for
+/// emitting code, etc.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICEASSEMBLER_H
 #define SUBZERO_SRC_ICEASSEMBLER_H
 
 #include "IceDefs.h"
 #include "IceFixups.h"
 #include "IceUtils.h"
 
@@ skipping 317 matching lines @@
 protected:
   // Buffer's constructor uses the Allocator, so it needs to appear after it.
   // TODO(jpp): dependencies on construction order are a nice way of shooting
   // yourself in the foot. Fix this.
   AssemblerBuffer Buffer;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEASSEMBLER_H_