Fixed PR14427 by handling old and new task_work interface.

Fixed PR14427 by handling old and new task_work interface.

* runtime/linux/autoconf-utrace-via-tracepoints.c: Just includes
  task_work.h to determine existence of task_work feature.
* runtime/linux/autoconf-task_work-struct.c: New file.
* buildrun.cxx (compile_pass): Add autoconf-task_work-struct test.
* runtime/linux/task_work_compatibility.h: New header that mask
  differences between old task_work interface and new one.
* runtime/linux/task_finder2.c: Handle removal of 'data' parameter from
  task_work struct by embedding stap_task_finder_target in
  __stp_tf_task_work structure.
* runtime/stp_task_work.c: Include task_work_compatibility.h instead of
  task_work.h.
* runtime/stp_utrace.c (utrace_task_alloc): Update init_task_work()
  function call to compatibility function call.