sim-fast-core: initial commit

New avr simulation core primarily based on translation and chaching
 along with simple combining/reworking of common instruction sequences.

	modified:   run_avr.c
	new file:   sim_fast_core.c
	new file:   sim_fast_core.h
	new file:   sim_fast_core_profiler.c
	new file:   sim_fast_core_profiler.h