fix doxygen brief in subzero header files

src/IceLiveness.cpp

 //===- subzero/src/IceLiveness.cpp - Liveness analysis implementation -----===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
-/// This file provides some of the support for the Liveness class. In
-/// particular, it handles the sparsity representation of the mapping between
-/// Variables and CfgNodes. The idea is that since most variables are used only
-/// within a single basic block, we can partition the variables into "local" and
-/// "global" sets. Instead of sizing and indexing vectors according to
-/// Variable::Number, we create a mapping such that global variables are mapped
-/// to low indexes that are common across nodes, and local variables are mapped
-/// to a higher index space that is shared across nodes.
+/// \brief Provides some of the support for the Liveness class.
+
+/// In particular, it handles the sparsity representation of the mapping
+/// between Variables and CfgNodes. The idea is that since most variables are
+/// used only within a single basic block, we can partition the variables into
+/// "local" and "global" sets. Instead of sizing and indexing vectors according
+/// to Variable::Number, we create a mapping such that global variables are
+/// mapped to low indexes that are common across nodes, and local variables are
+/// mapped to a higher index space that is shared across nodes.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceLiveness.h"
 
 #include "IceCfg.h"
 #include "IceCfgNode.h"
 #include "IceDefs.h"
 #include "IceInst.h"
 #include "IceOperand.h"
@@ skipping 100 matching lines @@
 }
 
 Variable *Liveness::getVariable(SizeT LiveIndex, const CfgNode *Node) const {
   if (LiveIndex < NumGlobals)
     return LiveToVarMap[LiveIndex];
   SizeT NodeIndex = Node->getIndex();
   return Nodes[NodeIndex].LiveToVarMap[LiveIndex - NumGlobals];
 }
 
 } // end of namespace Ice