gdb/

gdb/
	Make linux_get_siginfo_type `type *' unique.
	* linux-tdep.c (linux_gdbarch_data_handle, struct linux_gdbarch_data)
	(init_linux_gdbarch_data, get_linux_gdbarch_data): New.
	(linux_get_siginfo_type): New variable linux_gdbarch_data.  Initialize
	it.  Use linux_gdbarch_data->siginfo_type as a persistent storage.
	(_initialize_linux_tdep): New.