[ARC] Various small miscellaneous fixes.

[ARC] Various small miscellaneous fixes.

gcc/
2016-11-04  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (arc_process_double_reg_moves): Use
	gen_dexcl_2op call.
	* config/arc/arc.md (movsi_insn): Disable unsupported move
	instructions for ARCv2 cores.
	(movdi): Use prepare_move_operands.
	(movsf, movdf): Use move_dest_operand predicate.
	* config/arc/constraints.md (Chs): Enable when barrel shifter is
	present.
	* config/arc/fpu.md (divsf3): Change to divsf3_fpu.
	* config/arc/fpx.md (dexcl_3op_peep2_insn): Dx data register is
	also a destination.
	(dexcl_3op_peep2_insn_nores): Likewise.
	* config/arc/arc.h (SHIFT_COUNT_TRUNCATED): Define to one.
	(LINK_COMMAND_SPEC): Remove.

From-SVN: r241842