* Makefile.in (acconfig_h): Remove incorrect macro.

	* Makefile.in (acconfig_h): Remove incorrect macro.
	(config_h): Define.
	(osabi.o): Update dependencies.
	* configure.tgt: Set gdb_osabi based on target triplet.
	* configure.in: Define GDB_OSABI_DEFAULT based on gdb_osabi.
	* configure: Regenerated.
	* config.in: Regenerated.
	* osabi.c: Include "arch-utils.h", "gdbcmd.h", and "command.h".
	(GDB_OSABI_DEFAULT): Define if not already defined.
	(user_osabi_state, user_selected_osabi, gdb_osabi_available_names)
	(set_osabi_string): New variables.
	(gdbarch_register_osabi): Add new OS ABI to
	gdb_osabi_available_names.
	(gdbarch_lookup_osabi): Honor specified and default OS ABIs.
	(set_osabi, show_osabi): New functions.
	(_initialize_gdb_osabi): Add "set osabi" and "show osabi" commands.