[Ada] Small overhaul in Repinfo unit

[Ada] Small overhaul in Repinfo unit

This creates a List_Type_Info procedure to deal with type entities other
than arrays and records at top level and a List_Common_Type_Info
procedure to handle the common part between them.  No functional
changes.

2019-07-08  Eric Botcazou  <ebotcazou@adacore.com>

gcc/ada/

	* repinfo.adb (List_Common_Type_Info): New procedure extracted
	from...
	(List_Type_Info): ...here.  Call it for the common information,
	start with a blank line and output the linker section at the
	end, if any.
	(List_Mechanisms): Rename to...
	(List_Subprogram_Info): ...this.
	(List_Array_Info): Call List_Common_Type_Info.
	(List_Entities): Adjust to above change and renaming.
	(List_Record_Info): Call List_Common_Type_Info.

From-SVN: r273226