* i386-tdep.h (struct gdbarch_tdep): Replace sigtramp_saved_pc

* i386-tdep.h (struct gdbarch_tdep): Replace sigtramp_saved_pc
with sigcontext_addr.  Add sc_sp_offset.
(i386bsd_sigtramp_saved_pc): Remove prototype.
(i386bsd_sicontext_addr): Add prototype.
* i386-tdep.c (i386_sigtramp_saved_pc): New function.
(i386_frame_saved_pc): Rewrite to call i386_sigtramp_saved_pc.
(i386_svr4_sigtramp_saved_pc): Removed.
(i386_svr4_sigcontext_addr): New function.
(i386_svr4_init_abi): Don't initialize tdep->sigtramp_saved_pc.
Initialize tdep->sigcontext_addr instead.  Initialize
tdep->sc_pc_offset and tdep->sc_sp_offset.
(i386_gdbarch_init): Likewise.
* i386bsd-tdep.c (i386bsd_sigcontext_addr): Don't make it static
any more.
(i386bsd_sigtramp_saved_pc): Remove function.
(i386bsd_init_abi): Don't initialize tdep->sigtramp_saved_pc.
Initialize tdep->sigcontext_addr instead.  Initialize
tdep->sc_pc_offset.
* i386-linux-tdep.c (i386_linux_init_abi): Remove initialization
of tdep->sigtramp_saved_pc.
* i386-sol2-tdep.c (i386_sol2_init_abi): Don't initialize
tdep->sigtramp_saved_pc.  Initialize tdep->sigcontext_addr
instead.