[Ada] Skip entity name qualification in GNATprove mode

[Ada] Skip entity name qualification in GNATprove mode

GNATprove was using the qualification of names for entities with local
homonyms in the same scope, requiring the use of a suffix to
differentiate them. This caused problems for correctly identifying
primitive equality operators. This case is now handled like the rest of
entities in GNATprove, by instead updating Unique_Name to append the
suffix on-the-fly where needed.

There is no impact on compilation and hence no test.

2019-09-18  Yannick Moy  <moy@adacore.com>

gcc/ada/

	* exp_dbug.adb (Append_Homonym_Number): Use new function
	Get_Homonym_Number.
	(Get_Homonym_Number): New function to return the homonym number.
	(Qualify_Entity_Name): Remove special case for GNATprove.
	* exp_dbug.ads (Get_Homonym_Number): Make the new function
	public for use in GNATprove.
	* frontend.adb (Frontend): Do not qualify names in GNATprove
	mode.
	* sem_util.adb (Unique_Name): Append homonym suffix where needed
	for entities which have local homonyms in the same scope.

From-SVN: r275850