tests failing on s390x (1.7.0-rc2) on Fedora rawhide

[spotaws]

(note that the log reports 1.7-rc1, but source is built from the 1.7.0-rc2 tag)

   libunwind 1.7-rc1: tests/test-suite.log
=============================================
# TOTAL: 32
# PASS:  29
# SKIP:  0
# XFAIL: 0
# FAIL:  3
# XPASS: 0
# ERROR: 0
.. contents:: :depth: 2
FAIL: Gtest-resume-sig-rt
=========================
FAIL Gtest-resume-sig-rt (exit status: 134)
FAIL: Ltest-resume-sig-rt
=========================
FAIL Ltest-resume-sig-rt (exit status: 134)
FAIL: test-ptrace
=================
Automated test (self,ls,/,(null))
FAILURE: unw_step() returned -8 for ip=3ff9c50dbd8 (start ip=3ff9c89fbc6)
unwind failed with ret=-8
FAILURE: unw_step() returned -8 for ip=3ff9c700890 (start ip=3ff9c89fbc6)
unwind failed with ret=-8
FAILURE: unw_step() returned -8 for ip=3ff9c781868 (start ip=3ff9c89fbc6)
unwind failed with ret=-8
FAILURE: unw_step() returned -8 for ip=3ff9c8acf98 (start ip=3ff9c615ff6)
unwind failed with ret=-8
FAILURE: unw_step() returned -8 for ip=3ff9c8acf98 (start ip=3ff9c5e74b6)
unwind failed with ret=-8
FAILURE: unw_step() returned -8 for ip=3ff9c8acf98 (start ip=3ff9c5e74b6)
unwind failed with ret=-8
FAILURE: detected 12 errors
FAIL test-ptrace (exit status: 255)

[sharkcz]

FWIW all tests from the master branch seems to be passing OK on Fedora 36 on s390x