2013-04-22  Yannick Moy  <moy@adacore.com>

	* exp_prag.adb (Expand_Pragma_Loop_Variant): Rewrite pragma as
	null statement if ignored.
	* sem_ch6.adb (Expand_Contract_Cases): Do nothing if pragma is ignored.
	* sem_prag.adb (Analyze_Pragma): Keep analyzing ignored pragmas.

From-SVN: r198135