s-stchop-vxworks.adb (Set_Stack_Info): Instead of trying to map the VxWorks task descriptor in the Ada run time...

2007-04-20  Matthew Gingell  <gingell@adacore.com>
	    Jose Ruiz  <ruiz@adacore.com>

	* s-stchop-vxworks.adb (Set_Stack_Info): Instead of trying to map the
	VxWorks task descriptor in the Ada run time, call a C subprogram
	(__gnat_get_stack_info) that extracts the required information.

	* sysdep.c: Back out temporary lynxos workaround.
	(__gnat_get_stack_info): Add this procedure that passes to the Ada run
	time the stack information associated to the currently executing task.
	Only VxWorks systems require this function.

From-SVN: r125471