[ARC] Cleanup unused functions.

[ARC] Cleanup unused functions.

Remove unused pieces of code.

gcc/
2018-03-06  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (arc_finalize_pic): Remove function.
	(arc_must_save_register): We use single base PIC register, remove
	checks to save/restore the PIC register.
	(arc_expand_prologue): Likewise.
	* config/arc/arc-protos.h (arc_set_default_type_attributes):
	Remove.
	(arc_verify_short): Likewise.
	(arc_attr_type): Likewise.
	* config/arc/arc.c (arc_set_default_type_attributes): Remove.
	(walk_stores): Likewise.
	(arc_address_cost): Make it static.
	(arc_verify_short): Likewise.
	(branch_dest): Likewise.
	(arc_attr_type): Likewise.
	* config/arc/arc.c (TARGET_ADJUST_INSN_LENGTH): Remove.
	(TARGET_INSN_LENGTH_PARAMETERS): Likewise.
	(arc_final_prescan_insn): Remove inserting the nops due to
	hardware hazards.  It is done in reorg step.
	(insn_length_variant_t): Remove.
	(insn_length_parameters_t): Likewise.
	(arc_insn_length_parameters): Likewise.
	(arc_get_insn_variants): Likewise.
	* config/arc/arc.h (TARGET_UPSIZE_DBR): Remove.

From-SVN: r258275