GCN, nvptx offloading: Host/device compatibility: Itanium C++ ABI, DSO Object Destruc...

GCN, nvptx offloading: Host/device compatibility: Itanium C++ ABI, DSO Object Destruction API [PR119853, PR119854]

'__dso_handle' for '__cxa_atexit', '__cxa_finalize'.  See
<https://itanium-cxx-abi.github.io/cxx-abi/abi.html#dso-dtor>.

	PR target/119853
	PR target/119854
	libgcc/
	* config/gcn/crt0.c (_fini_array): Call
	'__GCC_offload___cxa_finalize'.
	* config/nvptx/gbl-ctors.c (__static_do_global_dtors): Likewise.
	libgomp/
	* target-cxa-dso-dtor.c: New.
	* config/accel/target-cxa-dso-dtor.c: Likewise.
	* Makefile.am (libgomp_la_SOURCES): Add it.
	* Makefile.in: Regenerate.
	* testsuite/libgomp.c++/target-cdtor-1.C: New.
	* testsuite/libgomp.c++/target-cdtor-2.C: Likewise.

(cherry picked from commit aafe942227baf8c2bcd4cac2cb150e49a4b895a9)