expmed.c (shift_cost, [...]): Additionally index by machine mode.

	* expmed.c (shift_cost, shiftadd_cost, shiftsub_cost): Additionally
	index by machine mode.
	(init_expmed): Initialize shift_cost, shiftadd_cost and shiftsub_cost
	tables inside the loop over machine modes.
	(synth_mult, expand_mult_highpart_optab, expand_mult_highpart,
	expand_divmod): Index shift*_cost by the appropriate machine mode.

From-SVN: r83053