config/s390/s390.c (s390_secondary_input_reload_class,
s390_plus_operand, s390_expand_plus_operand): New functions.
(struct s390_address): New member 'pointer'.
(s390_decompose_address): Compute it.
(legitimate_la_operand_p): Use it.
(legitimize_la_operand): New function.
(movti, movdi, movdf splitters): Call it.