* i386-tdep.c (i386_epilogue_frame_cache): Simplify code. Call

* i386-tdep.c (i386_epilogue_frame_cache): Simplify code.  Call
get_frame_func instead of get_frame_pc to determine the code
address used to construct the frame ID.
(i386_epilogue_frame_unwind_stop_reason): Fix coding style.
(i386_epilogue_frame_this_id): Likewise.
(i386_epilogue_frame_prev_register): New function.
(i386_epilogue_frame_unwind): Use i386_epilogue_frame_prev_register.
(i386_stack_tramp_frame_sniffer): Fix coding style.
(i386_stack_tramp_frame_unwind): Use i386_epilogue_frame_prev_register.
(i386_gdbarch_init): Fix comments.