(output_op_from_reg): Handle 3-word XFmode values.

(output_to_reg): Likewise.
(output_move_double): Handle XFmode operands.
(output_move_const_single): Use REAL_VALUE_TO_TARGET_SINGLE.
(print_operand): Add letter `T', size `12'.  Use REAL_VALUE macros
 to convert floating point operands.
(convert_387_op):  Add XFmode to case FLOAT_EXTEND.

From-SVN: r5571