[Ada] Ignore exceptions in task termination handlers

This patch fixes a bug in which if the environment task has a specific
termination handler, and that handler raises an exception, the handler
is called recursively, causing infinite recursion. The RM requires such
exceptions to be ignored.

gcc/ada/

	* libgnarl/s-solita.adb (Task_Termination_Handler_T): Ignore all
	exceptions propagated by Specific_Handler.
	* libgnarl/s-tassta.adb, libgnarl/s-taskin.ads: Minor.

gcc/ada/libgnarl/s-solita.adb

@@ -188,7 +188,14 @@ package body System.Soft_Links.Tasking is
       --  fall-back handler applies only to the dependent tasks of the task".
 
       if Self_Id.Common.Specific_Handler /= null then
-         Self_Id.Common.Specific_Handler.all (Cause, Self_Id, EO);
+         begin
+            Self_Id.Common.Specific_Handler.all (Cause, Self_Id, EO);
+         exception
+            --  RM-C.7.3(16) requires all exceptions raised here to be ignored
+
+            when others =>
+               null;
+         end;
       end if;
    end Task_Termination_Handler_T;
 

gcc/ada/libgnarl/s-taskin.ads

@@ -1168,7 +1168,7 @@ package System.Tasking is
       --
       --  Protection: Self.L. Once a task has set Self.Stage to Completing, it
       --  has exclusive access to this field.
-   end record;
+   end record; -- Ada_Task_Control_Block
 
    --------------------
    -- Initialization --

gcc/ada/libgnarl/s-tassta.adb

@@ -1307,10 +1307,8 @@ package body System.Tasking.Stages is
       if TH /= null then
          begin
             TH.all (Cause, Self_ID, EO);
-
          exception
-
-            --  RM-C.7.3 requires all exceptions raised here to be ignored
+            --  RM-C.7.3(16) requires all exceptions raised here to be ignored
 
             when others =>
                null;