fix doxygen brief in subzero header files

src/IceCfgNode.h

 //===- subzero/src/IceCfgNode.h - Control flow graph node -------*- 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 CfgNode class, which represents a single basic block
-/// as its instruction list, in-edge list, and out-edge list.
+/// \brief Declares the CfgNode class, which represents a single basic block as
+/// its instruction list, in-edge list, and out-edge list.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICECFGNODE_H
 #define SUBZERO_SRC_ICECFGNODE_H
 
 #include "IceDefs.h"
 #include "IceInst.h" // InstList traits
 
 namespace Ice {
@@ skipping 102 matching lines @@
   InstNumberT InstCountEstimate = 0; /// rough instruction count estimate
   NodeList InEdges;                  /// in no particular order
   NodeList OutEdges;                 /// in no particular order
   PhiList Phis;                      /// unordered set of phi instructions
   InstList Insts;                    /// ordered list of non-phi instructions
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICECFGNODE_H