Hi Thomas,
These are the OpenACC specific changes, mostly the re-implementation of async-related acc_* runtime
library API functions to use the new backend plugin interfaces, in a non-target specific way.

Thanks,
Chung-Lin


	* oacc-async.c (get_goacc_thread): New function.
	(get_goacc_thread_device): New function.
	(lookup_goacc_asyncqueue): New function.
	(get_goacc_asyncqueue): New function.
	(acc_async_test): Adjust code to use new async design.
	(acc_async_test_all): Likewise.
	(acc_wait): Likewise.
	(acc_wait_async): Likewise.
	(acc_wait_all): Likewise.
	(acc_wait_all_async): Likewise.
	(acc_get_default_async): New API function.
	(acc_set_default_async): Likewise.
	(goacc_async_unmap_tgt): New function.
	(goacc_async_copyout_unmap_vars): Likewise.
	(goacc_async_free): Likewise.
	(goacc_init_asyncqueues): Likewise.
	(goacc_fini_asyncqueues): Likewise.
	* oacc-cuda.c (acc_get_cuda_stream): Adjust code to use new async
	design.
	(acc_set_cuda_stream): Likewise.
	* oacc-host.c (host_openacc_exec): Adjust parameters, remove 'async'.
	(host_openacc_register_async_cleanup): Remove.
	(host_openacc_async_exec): New function.
	(host_openacc_async_test): Adjust parameters.
	(host_openacc_async_test_all): Remove.
	(host_openacc_async_wait): Remove.
	(host_openacc_async_wait_async): Remove.
	(host_openacc_async_wait_all): Remove.
	(host_openacc_async_wait_all_async): Remove.
	(host_openacc_async_set_async): Remove.
	(host_openacc_async_synchronize): New function.
	(host_openacc_async_serialize): New function.
	(host_openacc_async_host2dev): New function.
	(host_openacc_async_dev2host): New function.
	(host_openacc_async_queue_callback): New function.
	(host_openacc_async_construct): New function.
	(host_openacc_async_destruct): New function.
	(struct gomp_device_descr host_dispatch): Remove initialization of old
	interface, add intialization of new async sub-struct.
	* oacc-init.c (acc_shutdown_1): Adjust to use gomp_fini_device.
	(goacc_attach_host_thread_to_device): Remove old async code usage, add
	initialization of per-thread default_async.
	* oacc-int.h (struct goacc_thread): Add default_async field.
	(goacc_init_asyncqueues): New declaration.
	(goacc_fini_asyncqueues): Likewise.
	(goacc_async_copyout_unmap_vars): Likewise.
	(goacc_async_free): Likewise.
	(get_goacc_asyncqueue): Likewise.
	(lookup_goacc_asyncqueue): Likewise.

	* oacc-mem.c (memcpy_tofrom_device): Adjust code to use new async
	design.
	(present_create_copy): Likewise.
	(delete_copyout): Likewise.
	(update_dev_host): Likewise.
	(gomp_acc_insert_pointer): Add async parameter, adjust code to use new
	async design.
	(gomp_acc_remove_pointer): Adjust code to use new async design.
	* oacc-parallel.c (GOACC_parallel_keyed): Likewise.
	(GOACC_enter_exit_data): Likewise.
	(goacc_wait): Likewise.
	(GOACC_update): Likewise.
	* oacc-plugin.c (GOMP_PLUGIN_async_unmap_vars): Remove.