fix doxygen brief in subzero header files

src/IceTLS.h

 //===- subzero/src/IceTLS.h - thread_local workaround -----------*- 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 macros for working around the lack of support for
-/// thread_local in MacOS 10.6. It assumes std::thread is written in terms of
-/// pthread. Define ICE_THREAD_LOCAL_HACK to enable the pthread workarounds.
+/// \brief Defines macros for working around the lack of support for
+/// thread_local in MacOS 10.6.
+///
+/// This assumes std::thread is written in terms of pthread. Define
+/// ICE_THREAD_LOCAL_HACK to enable the pthread workarounds.
 ///
 //===----------------------------------------------------------------------===//
 
 #ifndef SUBZERO_SRC_ICETLS_H
 #define SUBZERO_SRC_ICETLS_H
 
 ///
 /// @defgroup /IceTLS Defines 5 macros for unifying thread_local and pthread:
 /// @{
 ///
@@ skipping 79 matching lines @@
 #define ICE_TLS_GET_FIELD(FieldName) (FieldName)
 #define ICE_TLS_SET_FIELD(FieldName, Value) (FieldName = (Value))
 
 #endif // !ICE_THREAD_LOCAL_HACK
 
 ///
 /// @}
 ///
 
 #endif // SUBZERO_SRC_ICETLS_H