S/390: Add -mbackchain options to fix test failure.

gcc/testsuite/ChangeLog

	* gcc.dg/Wframe-address.c: S/390 requires the -mbackchain option to
	access arbitrary stack frames.
	* gcc.dg/Wno-frame-address.c: Likewise.

From-SVN: r231273

gcc/testsuite/ChangeLog

 2015-12-04  Dominik Vogt  <vogt@linux.vnet.ibm.com>
 
+	* gcc.dg/Wframe-address.c: S/390 requires the -mbackchain option to
+	access arbitrary stack frames.
+	* gcc.dg/Wno-frame-address.c: Likewise.
+
+2015-12-04  Dominik Vogt  <vogt@linux.vnet.ibm.com>
+
 	* gcc.target/s390/asm-machine-1.c: Updated.
 	* gcc.target/s390/asm-machine-2.c: Updated.
 	* gcc.target/s390/asm-machine-3.c: Updated.

gcc/testsuite/gcc.dg/Wframe-address.c

 /* { dg-do compile } */
 /* { dg-options "-Wframe-address" } */
+/* { dg-additional-options "-mbackchain" { target { s390*-*-* } } } */
 
 void* __attribute__ ((noclone, noinline))
 test_builtin_frame_address (unsigned i)

gcc/testsuite/gcc.dg/Wno-frame-address.c

 /* { dg-do compile } */
 /* { dg-skip-if "Cannot access arbitrary stack frames" { arm*-*-* hppa*-*-* visium-*-* } } */
 /* { 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.  */