openmp: Fix intermittent hanging of task-detach-6 libgomp tests [PR98738]

openmp: Fix intermittent hanging of task-detach-6 libgomp tests [PR98738]

This adds support for the task detach clause to taskwait and taskgroup, and
simplifies the handling of the detach clause by moving most of the extra
handling required for detach tasks to omp_fulfill_event.

2021-02-25  Kwok Cheung Yeung  <kcy@codesourcery.com>
	    Jakub Jelinek  <jakub@redhat.com>

	libgomp/

	PR libgomp/98738
	* libgomp.h (enum gomp_task_kind): Add GOMP_TASK_DETACHED.
	(struct gomp_task): Replace detach and completion_sem fields with
	union containing completion_sem and detach_team.  Add deferred_p
	field.
	(struct gomp_team): Remove task_detach_queue.
	* task.c: Include assert.h.
	(gomp_init_task): Initialize deferred_p and completion_sem fields.
	Rearrange initialization order of fields.
	(task_fulfilled_p): Delete.
	(GOMP_task): Use address of task as the event handle.  Remove
	initialization of detach field.  Initialize deferred_p field.
	Use automatic local for completion_sem.  Initialize detach_team field
	for deferred tasks.
	(gomp_barrier_handle_tasks): Remove handling of task_detach_queue.
	Set kind of suspended detach task to GOMP_TASK_DETACHED and
	decrement task_running_count.  Move finish_cancelled block out of
	else branch.  Relocate call to gomp_team_barrier_done.
	(GOMP_taskwait): Handle tasks with completion events that have not
	been fulfilled.
	(GOMP_taskgroup_end): Likewise.
	(omp_fulfill_event): Use address of task as event handle.  Post to
	completion_sem for undeferred tasks.  Clear detach_team if task
	has not finished.  For finished tasks, handle post-execution tasks,
	call gomp_team_barrier_wake if necessary, and free task.
	* team.c (gomp_new_team): Remove initialization of task_detach_queue.
	(free_team): Remove free of task_detach_queue.
	* testsuite/libgomp.c-c++-common/task-detach-1.c: Fix formatting.
	* testsuite/libgomp.c-c++-common/task-detach-2.c: Fix formatting.
	* testsuite/libgomp.c-c++-common/task-detach-3.c: Fix formatting.
	* testsuite/libgomp.c-c++-common/task-detach-4.c: Fix formatting.
	* testsuite/libgomp.c-c++-common/task-detach-5.c: Fix formatting.
	Change data-sharing of detach events on enclosing parallel to private.
	* testsuite/libgomp.c-c++-common/task-detach-6.c: Likewise.  Remove
	taskwait directive.
	* testsuite/libgomp.c-c++-common/task-detach-7.c: New.
	* testsuite/libgomp.c-c++-common/task-detach-8.c: New.
	* testsuite/libgomp.c-c++-common/task-detach-9.c: New.
	* testsuite/libgomp.c-c++-common/task-detach-10.c: New.
	* testsuite/libgomp.c-c++-common/task-detach-11.c: New.
	* testsuite/libgomp.fortran/task-detach-1.f90: Fix formatting.
	* testsuite/libgomp.fortran/task-detach-2.f90: Fix formatting.
	* testsuite/libgomp.fortran/task-detach-3.f90: Fix formatting.
	* testsuite/libgomp.fortran/task-detach-4.f90: Fix formatting.
	* testsuite/libgomp.fortran/task-detach-5.f90: Fix formatting.
	Change data-sharing of detach events on enclosing parallel to private.
	* testsuite/libgomp.fortran/task-detach-6.f90: Likewise.  Remove
	taskwait directive.
	* testsuite/libgomp.fortran/task-detach-7.f90: New.
	* testsuite/libgomp.fortran/task-detach-8.f90: New.
	* testsuite/libgomp.fortran/task-detach-9.f90: New.
	* testsuite/libgomp.fortran/task-detach-10.f90: New.
	* testsuite/libgomp.fortran/task-detach-11.f90: New.