* mn10300-tdep.c: wrote/fixed implementations of
mn10300_frame_chain, mn10300_init_extra_frame_info,
mn10300_frame_saved_pc
* config/mn10300/tm-mn10300.h: redefine INIT_EXTRA_FRAME_INFO
and INIT_FRAME_PC macros
Backtracing starting to work correctly.
* mn10300-tdep.c: made a lot more generic, ripping out code
from copied target (no more mn10300_scan_prologue,
init_extra_frame_info, and mn10300_fix_call_dummy calls)
* config/mn10300/tm-mn10300.h: undefine INIT_EXTRA_FRAME_INFO
and INIT_FRAME_PC macros
* mn10300-tdep.c (mn10300_push_arguments): rewrote
also removed code elsewhere that made use of RP_REGNUM
* config/mn10300/tm-mn10300.h: ripped out RP_REGNUM, V0_REGNUM,
ARG0_REGNUM, ARGLAST_REGNUM (all not appropriate for mn10300
arch.), redefined SAVED_PC_AFTER_CALL, EXTRACT_RETURN_VALUE,
EXTRACT_STRUCT_VALUE_ADDRESS, STORE_RETURN_VALUE