[Ada] Unnesting: fix handling of generic associations

2018-06-11  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

	* exp_unst.adb (Visit_Node): Skip generic associations.

From-SVN: r261408

gcc/ada/ChangeLog

+2018-06-11  Ed Schonberg  <schonberg@adacore.com>
+
+	* exp_unst.adb (Visit_Node): Skip generic associations.
+
 2018-06-11  Arnaud Charlet  <charlet@adacore.com>
 
 	* libgnat/memtrack.adb (fwrite): Remove second definition.

gcc/ada/exp_unst.adb

@@ -825,6 +825,13 @@ package body Exp_Unst is
                      return Skip;
                   end if;
 
+               --  Generic associations are not analyzed: the actuals are
+               --  transferred to renaming qnd subtype declarations that
+               --  are the ones that must be examined.
+
+               when N_Generic_Association =>
+                  return Skip;
+
                --  Indexed references can be uplevel if the type isn't static
                --  and if the lower bound (or an inner bound for a multi-
                --  dimensional array) is uplevel.