[Ada] Unnesting: fix handling of private types that are synchronized

2018-10-09  Ed Schonberg  <schonberg@adacore.com>

gcc/ada/

	* exp_unst.adb (In_Synchronized_Call): Handle properly private
	types whose full views are synchronized types, in order to
	recognize generated subprograms whose bodies must be considered
	reachable even if no direct calls to them are visible in the
	source.

From-SVN: r264974

gcc/ada/ChangeLog

 2018-10-09  Ed Schonberg  <schonberg@adacore.com>
 
+	* exp_unst.adb (In_Synchronized_Call): Handle properly private
+	types whose full views are synchronized types, in order to
+	recognize generated subprograms whose bodies must be considered
+	reachable even if no direct calls to them are visible in the
+	source.
+
+2018-10-09  Ed Schonberg  <schonberg@adacore.com>
+
 	* exp_ch4.adb (Expand_Modular_Op): When expanding an operation
 	on nonbinary modular types, convert the opersnds to an integer
 	type that is large enough to hold the modulus of the type, which

gcc/ada/exp_unst.adb

@@ -227,6 +227,12 @@ package body Exp_Unst is
       while Present (S) and then S /= Standard_Standard loop
          if Is_Concurrent_Type (S) then
             return True;
+
+         elsif Is_Private_Type (S)
+           and then Present (Full_View (S))
+           and then Is_Concurrent_Type (Full_View (S))
+         then
+            return True;
          end if;
 
          S := Scope (S);