* alpha-tdep.c (alpha_register_type): Change from _virtual_type.

    * alpha-tdep.c (alpha_register_type): Change from _virtual_type.
        (alpha_convert_flt_dbl, alpha_convert_dbl_flt): Remove.
        (alpha_lds, alpha_sts): New.
        (alpha_convert_register_p): Change from _register_convertible.
        (alpha_register_to_value): Change from _convert_to_virtual;
        restructure and fail for type sizes other than 4 or 8.
        (alpha_value_to_register): Similarly.
        (alpha_extract_return_value): Use alpha_sts.
        (alpha_store_return_value): Use alpha_lds.
        (alpha_gdbarch_init): Update hooks.