fix doxygen brief in subzero header files

src/IceTypeConverter.h

 //===- subzero/src/IceTypeConverter.h - Convert ICE/LLVM Types --*- 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 how to convert LLVM types to ICE types, and ICE types to
-/// LLVM types.
+/// \brief Defines how to convert LLVM types to ICE types, and ICE types to LLVM
+/// types.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICETYPECONVERTER_H
 #define SUBZERO_SRC_ICETYPECONVERTER_H
 
 #include "IceDefs.h"
 #include "IceTypes.h"
 #pragma clang diagnostic push
 #pragma clang diagnostic ignored "-Wunused-parameter"
@@ skipping 33 matching lines @@
   /// Add LLVM/ICE pair to internal tables.
   void addLLVMType(Type Ty, llvm::Type *LLVMTy);
 
   /// Converts types not in LLVM2IceMap.
   Type convertToIceTypeOther(llvm::Type *LLVMTy) const;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETYPECONVERTER_H