Convert define_insn into define_insn_and_split for various subdi patterns
that output multiple assembly instructions.

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

          * config/arm/arm.md (arm_subdi3): Convert define_insn into
          define_insn_and_split.
          (subdi_di_zesidi,subdi_di_sesidi): Likewise.
          (subdi_zesidi_di,subdi_sesidi_di,subdi_zesidi_zesidi): Likewise.