2012-12-05  Ed Schonberg  <schonberg@adacore.com>

	* aspects.ads, aspects.adb: Add aspect Relative_Deadline.
	* sem_ch13.adb (Analyze_Aspect_Specifications): Process aspect
	Relative_Deadline, and introduce the corresponding pragma within
	the task definition of the task type to which it applies.
	(Check_Aspect_At_Freeze_Point): Expression in a Relative_Deadline
	aspect is of type Time_Span.

From-SVN: r194214