[Ada] Do not create a master unless Tasking_Allowed

2019-07-04  Bob Duff  <duff@adacore.com>

gcc/ada/

	* sem_ch3.adb (Access_Definition): Do not create a master unless
	Tasking_Allowed. Otherwise, this fails on restricted runtimes.

From-SVN: r273060

gcc/ada/ChangeLog

+2019-07-04  Bob Duff  <duff@adacore.com>
+
+	* sem_ch3.adb (Access_Definition): Do not create a master unless
+	Tasking_Allowed. Otherwise, this fails on restricted runtimes.
+
 2019-07-04  Hristian Kirtchev  <kirtchev@adacore.com>
 
 	* sem_util.adb (Propagate_DIC_Attributes): Do not propagate the

gcc/ada/sem_ch3.adb

@@ -935,6 +935,7 @@ package body Sem_Ch3 is
       then
          if Is_Limited_Record (Desig_Type)
            and then Is_Class_Wide_Type (Desig_Type)
+           and then Tasking_Allowed
          then
             Build_Class_Wide_Master (Anon_Type);