[Ada] Minor tweak for coverage

[Eric Botcazou]

Tested on x86_64-suse-linux, applied on the mainline.


2019-08-30  Eric Botcazou  <ebotca...@adacore.com>

        * gcc-interface/trans.c (gnat_to_gnu): Do not set the location on an
        expression used for a tag.

-- 
Eric Botcazou
Index: gcc-interface/trans.c
===================================================================
--- gcc-interface/trans.c	(revision 275191)
+++ gcc-interface/trans.c	(working copy)
@@ -8727,10 +8727,16 @@ gnat_to_gnu (Node_Id gnat_node)
 	set_gnu_expr_location_from_node (gnu_result, gnat_node);
     }
 
-  /* Set the location information on the result if it's not a simple name.
+  /* Set the location information on the result if it's not a simple name
+     or something that contains a simple name, for example a tag, because
+     we don"t want all the references to get the location of the first use.
      Note that we may have no result if we tried to build a CALL_EXPR node
      to a procedure with no side-effects and optimization is enabled.  */
-  else if (kind != N_Identifier && gnu_result && EXPR_P (gnu_result))
+  else if (kind != N_Identifier
+	   && !(kind == N_Selected_Component
+		&& Chars (Selector_Name (gnat_node)) == Name_uTag)
+	   && gnu_result
+	   && EXPR_P (gnu_result))
     set_gnu_expr_location_from_node (gnu_result, gnat_node);
 
   /* If we're supposed to return something of void_type, it means we have