Better handling of 64 bit and mixed 32/64 bit architectures.

	Better handling of 64 bit and mixed 32/64 bit architectures.
	* hardware.scm (hw-update-word-modes!): New fn.
	* mach.scm (define-cpu)): Call mode-set-word-modes!,
	hw-update-word-modes!.
	(state-word-bitsize): Replace FIXME with requested check.
	(arch-analyze-insns!): Call mode-ensure-word-sizes-defined.
	* mode.scm (mode-find): Ignore INT,UINT.
	(-mode-word-sizes-kind): New global.
	(mode-set-word-modes!,mode-set-identical-word-bitsizes!,
	mode-set-biggest-word-bitsizes!,mode-ensure-word-sizes-defined): New fns.
	(mode-init!): Initialize -mode-word-sizes-kind.  Move initialization
	of mode-list to ...
	(mode-builtin!): ... here.  Initialize WI/UWI/AI/IAI to something
	unusable, correct values set later.
	(mode-finish!): Remove cruft.
	* html.scm (doc-init!): Call mode-set-biggest-word-bitsizes!.
	* opcodes.scm (opcodes-init!): Ditto.
	* rtx-funcs.scm (annul): Fix mode of pc.
	* cpu/ia64.cpu: Remove cruft that sets word modes.
	* cpu/xstormy16.cpu (define-cpu): Set word-bitsize.