fix doxygen brief in subzero header files

src/IceTranslator.cpp

 //===- subzero/src/IceTranslator.cpp - ICE to machine code ------*- 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 general driver class for translating ICE to machine
-/// code.
+/// \brief Defines the general driver class for translating ICE to machine code.
 ///
 //===----------------------------------------------------------------------===//
 
 #include "IceTranslator.h"
 
 #include "IceCfg.h"
 #include "IceClFlags.h"
 #include "IceDefs.h"
 #include "IceGlobalInits.h"
 #include "IceTargetLowering.h"
@@ skipping 33 matching lines @@
 void Translator::translateFcn(std::unique_ptr<Cfg> Func) {
   Ctx->optQueueBlockingPush(std::move(Func));
 }
 
 void Translator::lowerGlobals(
     std::unique_ptr<VariableDeclarationList> VariableDeclarations) {
   EmitterWorkItem *Item = new EmitterWorkItem(getNextSequenceNumber(),
                                               VariableDeclarations.release());
   Ctx->emitQueueBlockingPush(Item);
 }