[ARM][2/2] Remove old rtx costs

[ARM][2/2] Remove old rtx costs

	* config/arm/arm.opt (mold-rtx-costs): Delete.
	(mnew-generic-costs): Delete.
	* config/arm/arm-protos.h (struct tune_params): Delete rtx_costs field.
	* config/arm/arm.c (arm_rtx_costs_1): Delete.
	(arm_size_rtx_costs): Likewise.
	(arm_slowmul_rtx_costs): Likewise.
	(arm_fastmul_rtx_costs): Likewise.
	(arm_xscale_rtx_costs): Likewise.
	(arm_9e_rtx_costs): Likewise.
	(arm_slowmul_tune, arm_fastmul_tune, arm_strongarm_tune,
	arm_xscale_tune, arm_9e_tune, arm_v6t2_tune, arm_cortex_tune,
	arm_cortex_a8_tune, arm_cortex_a7_tune, arm_cortex_a15_tune,
	arm_cortex_a53_tune, arm_cortex_a57_tune, arm_cortex_a9_tune,
	arm_cortex_a12_tune, arm_v7m_tune, arm_v6m_tune, arm_fa726te_tune
	arm_cortex_a5_tune, arm_xgene1_tune, arm_marvell_pj4_tune,
	arm_cortex_a35_tune, arm_exynosm1_tune, arm_cortex_a73_tune,
	arm_cortex_m7_tune):
	Delete rtx_costs field.
	(arm_new_rtx_costs): Rename to...
	(arm_rtx_costs_internal): ... This.
	(arm_rtx_costs): Remove old way of doing rtx costs.

From-SVN: r241966