[Ada] Unnesting: robustify analysis of block statements

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

gcc/ada/

	* exp_ch7.adb (Check_Unnesting_Elaboration_Code): Add guard.

From-SVN: r261409

gcc/ada/ChangeLog

 2018-06-11  Ed Schonberg  <schonberg@adacore.com>
 
+	* exp_ch7.adb (Check_Unnesting_Elaboration_Code): Add guard.
+
+2018-06-11  Ed Schonberg  <schonberg@adacore.com>
+
 	* exp_unst.adb (Visit_Node): Skip generic associations.
 
 2018-06-11  Arnaud Charlet  <charlet@adacore.com>

gcc/ada/exp_ch7.adb

@@ -4002,10 +4002,8 @@ package body Exp_Ch7 is
       then
          Stat := First (Statements (Handled_Statement_Sequence (N)));
          while Present (Stat) loop
-            if Nkind (Stat) = N_Block_Statement then
-               exit;
-            end if;
-
+            exit when Nkind (Stat) = N_Block_Statement
+              and then Present (Identifier (Stat));
             Next (Stat);
          end loop;
 
@@ -4046,7 +4044,9 @@ package body Exp_Ch7 is
               First (Statements (Handled_Statement_Sequence (Elab_Body)));
 
             while Present (Stat) loop
-               if Nkind (Stat) = N_Block_Statement then
+               if Nkind (Stat) = N_Block_Statement
+                 and then Present (Identifier (Stat))
+               then
                   Set_Scope (Entity (Identifier (Stat)), Elab_Proc);
                end if;