re PR libstdc++/56468 (Clang exposes bug with unexpected forward-declaration of type_info)

	PR libstdc++/56468
	* libsupc++/exception_ptr.h (type_info): Declare.

From-SVN: r196709

libstdc++-v3/ChangeLog

 2013-03-16  Jonathan Wakely  <jwakely.gcc@gmail.com>
 
+	PR libstdc++/56468
+	* libsupc++/exception_ptr.h (type_info): Declare.
+
+2013-03-16  Jonathan Wakely  <jwakely.gcc@gmail.com>
+
 	PR libstdc++/56002
 	* include/std/mutex (lock_guard, unique_lock, lock): Define without
 	depending on _GLIBCXX_HAS_GTHREADS.

libstdc++-v3/libsupc++/exception_ptr.h

@@ -44,6 +44,8 @@ extern "C++" {
 
 namespace std 
 {
+  class type_info;
+
   /**
    * @addtogroup exceptions
    * @{
@@ -141,7 +143,7 @@ namespace std
       operator==(const exception_ptr&, const exception_ptr&)
 	_GLIBCXX_USE_NOEXCEPT __attribute__ ((__pure__));
 
-      const class type_info*
+      const class std::type_info*
       __cxa_exception_type() const _GLIBCXX_USE_NOEXCEPT
 	__attribute__ ((__pure__));
     };