* mach.scm (<derived-arch-data>): New member large-insn-word?.

	* mach.scm (<derived-arch-data>): New member large-insn-word?.
	(/adata-set-derived!): Set it.
	(adata-large-insn-word?): New function.
	* sim-arch.scm (/gen-cpuall-includes): Don't #include cgen-engine.h
	here.
	* sim-cpu.scm (cgen-cpu.h): #include it here.
	(/gen-cpu-defines): Define CGEN_INSN_WORD.
	(/gen-no-scache-semantic-fn): Use CGEN_INSN_WORD instead of
	CGEN_INSN_INT.
	* sim-decode.scm (/gen-idesc-decls): Ditto.
	(/gen-extract-case, /gen-decode-fn): Ditto.
	* sim-model.scm (/gen-model-insn-fn): Ditto.
	* sim.scm (gen-argbuf-type): Ditto.