[v3] libsupc++/vec.cc update

[Jason Merrill]

Fixes for a bug in the ABI.  Nobody has responded to my mail to the ABI
list, so I'm just checking it in, to both trunk and branch.

Alex, I've included the patch to the ABI document as well.

2001-03-20  Jason Merrill  <jason@redhat.com>

	* libsupc++/vec.cc (__cxa_vec_cleanup): New fn.
	(__cxa_vec_ctor, __cxa_vec_cctor, __cxa_vec_dtor): Call it.
	* libsupc++/cxxabi.h: Declare it.