Update clang to r339409.

Change-Id: I800772d2d838223be1f6b40d490c4591b937fca2
diff --git a/linux-x64/clang/include/llvm/Support/Signals.h b/linux-x64/clang/include/llvm/Support/Signals.h
index dec5f58..f25a049 100644
--- a/linux-x64/clang/include/llvm/Support/Signals.h
+++ b/linux-x64/clang/include/llvm/Support/Signals.h
@@ -29,7 +29,7 @@
 
   /// This function registers signal handlers to ensure that if a signal gets
   /// delivered that the named file is removed.
-  /// @brief Remove a file if a fatal signal occurs.
+  /// Remove a file if a fatal signal occurs.
   bool RemoveFileOnSignal(StringRef Filename, std::string* ErrMsg = nullptr);
 
   /// This function removes a file from the list of files to be removed on
@@ -38,7 +38,7 @@
 
   /// When an error signal (such as SIGABRT or SIGSEGV) is delivered to the
   /// process, print a stack trace and then exit.
-  /// \brief Print a stack trace if a fatal signal occurs.
+  /// Print a stack trace if a fatal signal occurs.
   /// \param Argv0 the current binary name, used to find the symbolizer
   ///        relative to the current binary before searching $PATH; can be
   ///        StringRef(), in which case we will only search $PATH.
@@ -50,16 +50,18 @@
   /// Disable all system dialog boxes that appear when the process crashes.
   void DisableSystemDialogsOnCrash();
 
-  /// \brief Print the stack trace using the given \c raw_ostream object.
+  /// Print the stack trace using the given \c raw_ostream object.
   void PrintStackTrace(raw_ostream &OS);
 
   // Run all registered signal handlers.
   void RunSignalHandlers();
 
-  /// AddSignalHandler - Add a function to be called when an abort/kill signal
-  /// is delivered to the process.  The handler can have a cookie passed to it
-  /// to identify what instance of the handler it is.
-  void AddSignalHandler(void (*FnPtr)(void *), void *Cookie);
+  using SignalHandlerCallback = void (*)(void *);
+
+  /// Add a function to be called when an abort/kill signal is delivered to the
+  /// process. The handler can have a cookie passed to it to identify what
+  /// instance of the handler it is.
+  void AddSignalHandler(SignalHandlerCallback FnPtr, void *Cookie);
 
   /// This function registers a function to be called when the user "interrupts"
   /// the program (typically by pressing ctrl-c).  When the user interrupts the
@@ -69,7 +71,7 @@
   /// functions.  An null interrupt function pointer disables the current
   /// installed function.  Note also that the handler may be executed on a
   /// different thread on some platforms.
-  /// @brief Register a function to be called when ctrl-c is pressed.
+  /// Register a function to be called when ctrl-c is pressed.
   void SetInterruptFunction(void (*IF)());
 } // End sys namespace
 } // End llvm namespace