* target.h (targetm.cxx.use_atexit_for_cxa_atexit): New target
	hook.
	* target-def.h: (TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT): Define
	default.
	* config/i386/mingw32.h (TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT):
	Override default.
	* doc/tm.texi (TARGET_CXX_USE_ATEXIT_FOR_CXA_ATEXIT): Document.
	* configure.ac (use_cxa_atexit): As a special case, don't test
	for libc definition of __cxa_atexit on mingw32
	* configure: Regenerate.
	* config.gcc (i[34567]86-pc-mingw32): Default to
	enable__cxa_atexit=yes.

cp

	* decl.c (get_atexit_node): Reference atexit, not __cxa_exit.
	if targetm.cxx.use_atexit_for cxa_atexit.
	(start_cleanup_fn): Likewise.
	(register_dtor_fn): Likewise.

From-SVN: r118371