[gdb/testsuite] Fix gdb.base/inline-frame-cycle-unwind.exp for s390x

This commit fixes six failures for s390x due to a fundamental
difference in unwinding behavior between s390x and other
architectures:

FAIL: gdb.base/inline-frame-cycle-unwind.exp: bt: cycle at level 5:
  backtrace when the unwind is broken at frame 5
FAIL: gdb.base/inline-frame-cycle-unwind.exp: bt: cycle at level 3:
  backtrace when the unwind is broken at frame 3
FAIL: gdb.base/inline-frame-cycle-unwind.exp: bt: cycle at level 1:
  backtrace when the unwind is broken at frame 1
FAIL: gdb.base/inline-frame-cycle-unwind.exp: bt -no-filters: cycle at level 5:
  backtrace when the unwind is broken at frame 5
FAIL: gdb.base/inline-frame-cycle-unwind.exp: bt -no-filters: cycle at level 3:
  backtrace when the unwind is broken at frame 3
FAIL: gdb.base/inline-frame-cycle-unwind.exp: bt -no-filters: cycle at level 1:
  backtrace when the unwind is broken at frame 1

The core issue is that on s390x, the Canonical Frame Address (CFA) for
a function points *into the caller's stack frame*, whereas on x86_64
or aarch64 the CFA points *within the current function's frame*.  This
architectural difference causes cycle detection to occur later on
s390x.

The patch resolves this by:
- Making expected backtrace output architecture-specific.
- For non-s390x targets: expecting the full set of frames up to the
  specified level.
- For s390x: expecting fewer frames before detecting the cycle
  (e.g., level 5 shows 3 frames instead of 5).
- Skipping the cycle at level 1 test entirely on s390x since it cannot
  be detected at that frame.

Tested using recent Fedora releases on s390x, x86_64, and aarch64.

0 files changed, 0 insertions, 0 deletions