* expmed.h (NUM_MODE_VECTOR_INT): Define.
(struct expmed_op_cheap, struct expmed_op_costs): New structures.
(struct target_expmed): Convert x_mul_highpart_cost and
x_mul_widen_cost fields to be indexed by integer modes.
Convert x_sdiv_pow2_cheap and x_smod_pow2_cheap fields to be
of type struct expmed_op_cheap. Convert other cost fields to be
of type struct_expmed_op_costs.
(mul_widen_cost_ptr, mul_highpart_cost_ptr): Adjust for new
indexing of respective fields.
(expmed_op_cheap_ptr): New function.
(sdiv_pow2_cheap_ptr, smod_pow2_cheap_ptr): Call it.
(expmed_op_cost_ptr): New function.
(add_cost_ptr, neg_cost_ptr, shift_cost_ptr, shiftadd_cost_ptr,
shiftsub0_cost_ptr, shiftsub1_cost_ptr, mul_cost_ptr,
sdiv_cost_ptr, udiv_cost_ptr): Call it.