S/390: Add -mbackchain to frame-address tests.

gcc/testsuite/ChangeLog

	* g++.dg/Wframe-address.C: Test requires -mbackchain for s390*-*-*
	* g++.dg/Wno-frame-address.C: Ditto.

From-SVN: r232421

gcc/testsuite/ChangeLog

 2016-01-15  Dominik Vogt  <vogt@linux.vnet.ibm.com>
 
+	* g++.dg/Wframe-address.C: Test requires -mbackchain for s390*-*-*.
+	* g++.dg/Wno-frame-address.C: Ditto.
+
+2016-01-15  Dominik Vogt  <vogt@linux.vnet.ibm.com>
+
 	* gcc.dg/tree-ssa/20040204-1.c: Do not xfail on S/390.
 
 2016-01-15  Richard Biener  <rguenther@suse.de>

gcc/testsuite/g++.dg/Wno-frame-address.C

 // { dg-do compile }
 // { dg-skip-if "Cannot access arbitrary stack frames." { arm*-*-* hppa*-*-* } }
 // { dg-options "-Werror" }
+// { dg-additional-options "-mbackchain" { target s390*-*-* } }
 
 // Verify that -Wframe-address is not enabled by default by enabling
 // -Werror and verifying the test still compiles.