Failures on Debian-s390x-native-gdbserver-m64, branch master

[sergiodj+buildbot@sergiodj.net]

Buildslave:
	debian-jessie-s390x-1

Full Build URL:
	<http://gdb-build.sergiodj.net/builders/Debian-s390x-native-gdbserver-m64/builds/4017>

Commit(s) tested:
	03b039a518fa0f89a9900a44a8b874cc91061305

Author(s) (in the same order as the commits):
	Kito Cheng <kito.cheng@gmail.com>

Subject:
	RISC-V: Fix assembler for c.addi, rd can be x0

Testsuite log (gdb.sum and gdb.log) URL(s):
	<http://gdb-build.sergiodj.net/results/Debian-s390x-native-gdbserver-m64/03/03b039a518fa0f89a9900a44a8b874cc91061305/>