a-direct.adb (Start_Search): Check for Name_Error before checking for Use_Error, as specified in the RM.

2008-04-08  Vincent Celier  <celier@adacore.com>

	* a-direct.adb (Start_Search): Check for Name_Error before checking for
	Use_Error, as specified in the RM. Check if directory is open and raise
	Use_Error if it is not.

From-SVN: r134059