Create subdir data-directory.

	Create subdir data-directory.
	* Makefile.in (XML_SYSCALL_DIR, XML_SYSCALL_FILES): Moved to
	data-directory/Makefile.in.
	(SUBDIRS): Add data-directory.
	(all): Remove xml-syscall-copy dependency.
	(xml-syscall-copy): Moved to data-directory/Makefile.in as
	stamp-syscalls.
	(xml-syscall-install): Moved to data-directory/Makefile.in as
	install-syscalls.
	(install-only): Remove xml-syscall-install dependency.
	(all-data-directory): New rule.
	(data-directory/Makefile): New rule.
	* configure.ac (AC_OUTPUT): Add data-directory/Makefile.
	* configure: Regenerate.
	* data-directory/Makefile.in: New file.
	* python/lib/gdb/__init__.py: New file.

	testsuite/
	* gdb.base/catch-syscall.exp (do_syscall_tests): Update location
	of syscall staging area.