GDBserver self tests

GDBserver self tests

This patch uses GDB self test in GDBserver.  The self tests are run if
GDBserver is started with option --selftest.

gdb:

2017-08-18  Yao Qi  <yao.qi@linaro.org>

	* NEWS: Mention GDBserver's new option "--selftest".
	* Makefile.in (SFILES): Remove selftest.c, add common/selftest.c.
	* selftest.c: Move it to common/selftest.c.
	* selftest.h: Move it to common/selftest.h.
	* selftest-arch.c (reset): New function.
	(tests_with_arch): Call reset.

gdb/gdbserver:

2017-08-18  Yao Qi  <yao.qi@linaro.org>

	* Makefile.in (OBS): Add selftest.o.
	* configure.ac: AC_DEFINE GDB_SELF_TEST if $development.
	* configure, config.in: Re-generated.
	* server.c: Include common/sefltest.h.
	(captured_main): Handle option --selftest.

gdb/testsuite:

2017-08-18  Yao Qi  <yao.qi@linaro.org>

	* gdb.server/unittest.exp: New.

gdb/doc:

2017-08-18  Yao Qi  <yao.qi@linaro.org>

	* gdb.texinfo (Server): Document "--selftest".