fix doxygen brief in subzero header files

src/IceInstX86Base.h

 //===- subzero/src/IceInstX86Base.h - Generic x86 instructions -*- 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 defines the InstX86Base template class, as well as the generic X86
-/// Instruction class hierarchy. Only X86 instructions common across all/most
-/// X86 targets should be defined here, with target-specific instructions
-/// declared in the target's traits.
+/// \brief This file defines the InstX86Base template class, as well as the
+/// generic X86 Instruction class hierarchy.
+///
+/// Only X86 instructions common across all/most X86 targets should be defined
+/// here, with target-specific instructions declared in the target's traits.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICEINSTX86BASE_H
 #define SUBZERO_SRC_ICEINSTX86BASE_H
 
 #include "IceDefs.h"
 #include "IceInst.h"
 #include "IceOperand.h"
 
@@ skipping 3190 matching lines @@
           &InstX86Base<Machine>::Traits::Assembler::psrl};                     \
   }                                                                            \
   }
 
 } // end of namespace X86Internal
 } // end of namespace Ice
 
 #include "IceInstX86BaseImpl.h"
 
 #endif // SUBZERO_SRC_ICEINSTX86BASE_H