for mn10300_analyze_prologue.
(mn10300_analyze_prologue): Simplify by factoring out common code.
Fix bugs in setting frame address for optimized code.
Use read_memory_nobpt instead of target_read_memory.
* 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.