[Ada] ACATS 4.1H - B853001 - missed errors for renamed limited

[Ada] ACATS 4.1H - B853001 - missed errors for renamed limited

gcc/ada/

	* einfo.ads (Has_Limited_View): New synthesized attribute.
	* einfo.adb (Has_Limited_View): New synthesized attribute.
	(Set_Limited_View): Complete assertion.
	* sem_ch10.ads (Is_Visible_Through_Renamings): Make this routine
	public to invoke it from Find_Expanded_Name and avoid reporting
	spurious errors on renamings of limited-with packages.
	(Load_Needed_Body): Moved to have this spec alphabetically
	ordered.
	* sem_ch10.adb (Is_Visible_Through_Renamings): Moved to library
	level.
	(Is_Limited_Withed_Unit): New subprogram.
	* sem_ch3.adb (Access_Type_Declaration): Adding protection to
	avoid reading attribute Entity() when not available.
	* sem_ch8.adb (Analyze_Package_Renaming): Report error on
	renamed package not visible through context clauses.
	(Find_Expanded_Name): Report error on renamed package not
	visible through context clauses; handle special case where the
	prefix is a renaming of a (now visible) shadow package.