[sim/rx]

[sim/rx]
* README.txt: New.
* config.h (CYCLE_ACCURATE, CYCLE_STATS): New.
* configure.in (--enable-cycle-accurate, --enable-cycle-stats):
New.  Default to enabled.
* configure: Regenerate.

* cpu.h (regs_type): Add cycle tracking info.
(reset_pipeline_stats): Declare.
(halt_pipeline_stats): Declare.
(pipeline_stats): Declare.
* main.c (done): Call pipeline_stats().
* mem.h (rx_mem_ptr): Moved to here ...
* mem.c (mem_ptr): ... from here.  Rename throughout.
(mem_put_byte): Move LEDs to Port A.  Add Port B to control cycle
statistics.  Move UART to SCI4.
(mem_put_hi): Add TPU 1-2.  TPU 1 and 2 count CPU cycles.
* reg.c (init_regs): Set Rt reg to -1 (no reg).
* rx.c: Add cycle counting and statistics throughout.
(rx_get_byte): Optimize for speed.
(decode_opcode): Likewise.
(reset_pipeline_stats): New.
(halt_pipeline_stats): New.
(pipeline_stats): New.
* trace.c (sim_disasm_one): Print cycle count.

[include/opcode]
* rx.h (RX_Opcode_ID): Add nop2 and nop3 for statistics.