[ARC] Don't allow the last ZOL insn to be in a delay slot.

[ARC] Don't allow the last ZOL insn to be in a delay slot.

The ARC ZOL implementation doesn't allow the last instruction to be a
control instruction or part of a delay slot.  Thus, we add a note to
the last ZOL instruction which will prevent it to finish into a delay
slot.

2017-10-20  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (hwloop_optimize): Prevent the last
        ZOL instruction to end into a delay slot.
	* config/arc/arc.md (cond_delay_insn): Check if the instruction
	can be placed into a delay slot against reg_note.
	(in_delay_slot): Likewise.

testsuite/
2017-10-20  Claudiu Zissulescu  <claziss@synopsys.com>

	* gcc.target/arc/loop-3.c: New test.
	* gcc.target/arc/loop-4.c: Likewise.

[FIX][ZOL] fix checking for jumps

From-SVN: r255275