* amd64-linux-nat.c (compat_int_t, compat_uptr_t, compat_time_t)
(compat_timer_t, compat_clock_t, struct compat_timeval)
(compat_sigval_t, compat_siginfo_t): New types.
(cpt_si_pid, cpt_si_uid, cpt_si_timerid, cpt_si_overrun)
(cpt_si_status, cpt_si_utime, cpt_si_stime, cpt_si_ptr)
(cpt_si_addr, cpt_si_band, cpt_si_fd): New defines.
(compat_siginfo_from_siginfo, siginfo_from_compat_siginfo)
(amd64_linux_siginfo_fixup): New.
* linux-nat.c (linux_nat_siginfo_fixup): New.
(siginfo_fixup): New.
(linux_xfer_siginfo): Use siginfo_fixup to convert between the
siginfo layout expected by ptrace and the siginfo layout of the
inferior.
(linux_nat_set_siginfo_fixup): New.
* linux-nat.h (linux_nat_set_siginfo_fixup): Declare.