Failures on Fedora-ppc64le-native-gdbserver-m64, branch master

[sergiodj+buildbot@sergiodj.net]

Buildslave:
	fedora-ppc64le-1

Full Build URL:
	<http://gdb-build.sergiodj.net/builders/Fedora-ppc64le-native-gdbserver-m64/builds/5249>

Commit(s) tested:
	d194f1fe51cb85b8a919b7ee9e3a7715b0ec9744

Author(s) (in the same order as the commits):
	Pedro Alves <palves@redhat.com>

Subject:
	gdb::optional: Add observers

Testsuite log (gdb.sum and gdb.log) URL(s):
	<http://gdb-build.sergiodj.net/results/Fedora-ppc64le-native-gdbserver-m64/d1/d194f1fe51cb85b8a919b7ee9e3a7715b0ec9744/>