From Michal Ludvig <mludvig@suse.cz>:

From Michal Ludvig  <mludvig@suse.cz>:
* i386-tdep.h (struct gdbarch_tdep): Add members `sc_reg_offset'
and `sc_num_regs'.
(I386_EAX_REGNUM, I386_EDX_REGNUM, I386_ESP_REGNUM,
I386_EBP_REGNUM, I386_EIP_REGNUM, I386_EFLAGS_REGNUM,
I386_ST0_REGNUM): Move here from...
* i386-tdep.c: ... here.
(I386_NUM_SAVED_REGS): Define to I386_NUM_REGS.
(i386_sigtramp_frame_cache): Use `sc_reg_offset' to find saved
registers if possible.
(i386_gdbarch_init): Initialize TDEP->sc_reg_offset.
* i386bsd-tdep.c (i386bsd_sc_pc_offset, i386bsd_sc_sp_offset):
Remove variables.
(i386bsd_sc_reg_offset): New variable.
(i386bsd_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
TDEP->sc_sp_offset.
(i386fbsd_sc_reg_offset): New variable.
(i386fbsdaout_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs.
(i386fbsd4_sc_pc_offset, i386fbsd4_sc_sp_offset): Remove
variables.
(i386fbsd4_sc_reg_offset): New variable.
(i3864bsd4_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
TDEP->sc_sp_offset.
* i386-linux-tdep.c (i386_linux_sc_reg_offset): New variable.
(i386_linux_init_abi): Set TDEP->sc_reg_offset and TDEP->sc_num_regs.
* i386nbsd-tdep.c (i386nbsd_sc_pc_offset, i386nbsd_sc_sp_offset):
Remove variables.
(i386nbsd_sc_reg_offset): New variable.
(i386nbsd_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
TDEP->sc_sp_offset.
* i386obsd-tdep.c (i386obsd_sc_pc_offset, i386obsd_sc_sp_offset):
Remove variables.
(i386obsd_sc_reg_offset): New variable.
(i386obsd_init_abi): Initialize TDEP->sc_reg_offset and
TDEP->sc_num_regs instead of TDEP->sc_pc_offset and
TDEP->sc_sp_offset.
* i386bsd-nat.c (_initialize_i386bsd_nat): Adjust for changes in
i386bsd-tdep.c, i386nbsd-tdep.c and i386obsd-tdep.c.  Add check
for frame pointer offset in `struct sigcontext'.