Convert define_insn into define_insn_and_split for various DImode shift
operations that output multiple assembly instructions.

This patch also adds a new pattern for RRX using a new UNSPEC. This pattern
matches RTL insns emitted by arm_ashrdi3_1bit and arm_lshrdi3_1bit
splitters. This patch also adds a new pattern shiftsi3_compare.

gcc/

2013-02-14  Greta Yorsh  <Greta.Yorsh@arm.com>

      * config/arm/arm.md (arm_ashldi3_1bit): Convert define_insn into
      define_insn_and_split.
        (arm_ashrdi3_1bit,arm_lshrdi3_1bit): Likewise.
      (shiftsi3_compare): New pattern.
      (rrx): New pattern.
      * config/arm/unspecs.md (UNSPEC_RRX): New.