Ada: Fix spurious visibility error from limited_with clause in hierarchy

The problem is that the compiler installs the limited view of a package that
is already installed by the virtue of being an ancestor of the main unit.

gcc/ada/
	PR ada/123867
	* sem_ch10.adb (Analyze_Compilation_Unit): Output info message
	when -gnatdi is specified.
	(Install_Parents): Likewise.  Set the Is_Visible_Lib_Unit flag
	on the unit.
	(Install_Private_With_Clauses): Do not output info message here.
	(Remove_Parents): Output info message when -gnatdi is specified
	and clear the Is_Visible_Lib_Unit flag on the unit.

gcc/testsuite/
	* gnat.dg/specs/limited_with3.ads: New test.
	* gnat.dg/specs/limited_with3-child.ads: New helper.
	* gnat.dg/specs/limited_with3-child-grandchild.ads: Likewise.
	* gnat.dg/specs/limited_with3-child-grandchild-grandgrandchild.ads:
	Likewise.