* m68k-tdep.h (struct gdbarch_tdep): New fields
	float_return, fpreg_type, coldire, fido and
	fpregs_present.
	* m68k-tdep.c (m68k_register_type): Use
	fpregs_present and fpreg_type.
	(m68k_register_names): New.
	(m68k_register_name): Use the above.
	(m68k_convert_register_p): Consult fpregs_present.
	(m68k_register_to_value, m68k_value_to_register):
	Use register_type to obtain the type of floating
	point registers.
	(m68k_svr4_extract_return_value): Check tdep->float_return.
	Use register_type to get the type of floating
	point regiters.
	(m68k_svr4_store_return_value): Likewise.
	(m68k_dwarf_reg_to_regnum): Check tdep->fpregs_present.
	(m68k_analyze_register_saves): Likewise.
	(m68k_gdbarch_init): Extract infromation
	from XML description, if present.  Guess coldfire by
	looking at the file, if present. Conditionalize
	setting of long double format.  Set decr_pc_after_break
	to 2 on coldfire and fido.  Enable XML-driven
	register description.
	* m68kbsd-tdep.c (m68kbsd_fpreg_offset): Use
	size of tdep->fpreg_type, as opposed to hardcoded value.