* insn.scm (/parse-insn-format): New arg `verify?', all callers updated.

	* insn.scm (/parse-insn-format): New arg `verify?', all callers updated.
	(/insn-parse): Don't verify iformat for virtual insns.

	* sid-decode.scm (cgen-decode.cxx): Remove redundant call to
	non-multi-insns.
	* sid-model.scm (/gen-model-insn-fn-decls): Ditto.
	(/gen-model-insn-fns, /gen-model-class-decls): Ditto.
	* sid.scm (pbb-engine-insns): Ditto.
	* sim-decode.scm (cgen-decode.c): Ditto.