exp_attr.adb (Expand_N_Attribute_Reference): Make sure prefix of constructed 'Valid attribute in -gnatVa mode does not...

2014-08-04  Robert Dewar  <dewar@adacore.com>

	* exp_attr.adb (Expand_N_Attribute_Reference): Make sure prefix
	of constructed 'Valid attribute in -gnatVa mode does not appear
	to come from source.
	* sem_attr.adb (Analyze_Access_Attribute): Don't set
	Never_Set_In_Source for non-source reference.
	* sem_util.adb: Minor reformatting.
	* sem_warn.adb (Check_References): Don't check Address_Taken,
	not necessary, see comment.

From-SVN: r213568