Failures on Debian-s390x-native-extended-gdbserver-m64, branch gdb-8.1-branch

[sergiodj+buildbot@sergiodj.net]

Buildslave:
	debian-jessie-s390x-1

Full Build URL:
	<http://gdb-build.sergiodj.net/builders/Debian-s390x-native-extended-gdbserver-m64/builds/5689>

Commit(s) tested:
	8679931c2c9f97ad182f8f0a9e8fab20305719b5

Author(s) (in the same order as the commits):
	Omair Javaid <omair.javaid@linaro.org>

Subject:
	Unset gdbarch significant_addr_bit by default

Testsuite log (gdb.sum and gdb.log) URL(s):
	<http://gdb-build.sergiodj.net/results/Debian-s390x-native-extended-gdbserver-m64/86/8679931c2c9f97ad182f8f0a9e8fab20305719b5/>