PR libstdc++/38732
	* libsupc++/unwind-cxx.h (__cxxabiv1::__cxa_exception): Remove
	referenceCount field again.
	(__cxxabiv1::__cxa_refcounted_exception): New struct.
	(__cxxabiv1::__get_refcounted_exception_header_from_obj,
	__cxxabiv1::__get_refcounted_exception_header_from_ue): New static
	inline functions.
	* libsupc++/eh_alloc.cc (__cxxabiv1::__cxa_allocate_exception,
	__cxxabiv1::__cxa_free_exception): Use __cxa_refcounted_exception
	instead of __cxa_exception.
	* libsupc++/eh_throw.cc (__gxx_exception_cleanup,
	__cxxabiv1::__cxa_throw): Likewise.
	* libsupc++/eh_ptr.cc (std::rethrow_exception,
	std::__exception_ptr::exception_ptr::_M_addref,
	std::__exception_ptr::exception_ptr::_M_release,
	__gxx_dependent_exception_cleanup): Likewise.
	* testsuite/18_support/exception/38732.cc: New test.

From-SVN: r143170