Long-standing FAIL remedied; committed. Maybe better to list
the targets that *do* support arbitrary frame access?
gcc/testsuite:
* gcc.dg/Wno-frame-address.c: Skip for cris and mmix.
/* { dg-do compile } */
-/* { dg-skip-if "Cannot access arbitrary stack frames" { arm*-*-* amdgpu-*-* avr-*-* hppa*-*-* ia64-*-* visium-*-* csky-*-* msp430-*-* } } */
+/* { dg-skip-if "Cannot access arbitrary stack frames" { arm*-*-* amdgpu-*-* avr-*-* hppa*-*-* ia64-*-* visium-*-* csky-*-* msp430-*-* cris-*-* mmix-*-* } } */
/* { dg-options "-Werror" } */
/* { dg-additional-options "-mbackchain" { target { s390*-*-* } } } */