re PR bootstrap/68361 (Bootstrap failure with --enable-checking=release)

	PR bootstrap/68361

	* cvt.c (cp_convert_and_check): Use warning_sentinel to suppress
	-Wparentheses.

From-SVN: r230470

gcc/cp/ChangeLog

+2015-11-17  Jason Merrill  <jason@redhat.com>
+
+	PR bootstrap/68361
+	* cvt.c (cp_convert_and_check): Use warning_sentinel to suppress
+	-Wparentheses.
+
 2015-11-16  Jason Merrill  <jason@redhat.com>
 
 	* constexpr.c (cxx_eval_builtin_function_call): Use cp_fully_fold

gcc/cp/cvt.c

@@ -644,7 +644,7 @@ cp_convert_and_check (tree type, tree expr, tsubst_flags_t complain)
       else
 	{
 	  /* Avoid bogus -Wparentheses warnings.  */
-	  TREE_NO_WARNING (folded) = true;
+	  warning_sentinel w (warn_parentheses);
 	  folded_result = cp_convert (type, folded, tf_none);
 	}
       folded_result = fold_simple (folded_result);

gcc/testsuite/g++.dg/warn/Wparentheses-28.C

+// PR bootstrap/68361
+// { dg-options -Wparentheses }
+
+struct A
+{
+  int p: 2;
+};
+
+A a, b;
+
+int main()
+{
+  bool t = (a.p = b.p);
+}