Add extra flags to help new CPU handle various instructions.

Add extra flags to help new CPU handle various instructions.
IsIprAccess flag may go away in the future (op class can be used to tell this), and the CPU still needs a specific way to identify/deal with syscalls.

arch/alpha/isa/decoder.isa:
    Added a few extra flags to help the new CPU identify various classes of instructions without having to force certain behaviors for all CPUs.
cpu/base_dyn_inst.hh:
cpu/static_inst.hh:
    Added extra flags.
cpu/o3/iew_impl.hh:
cpu/o3/inst_queue_impl.hh:
    Handle store conditionals specially.
cpu/o3/lsq_unit_impl.hh:
    Extra flags tells if the instruction is a store conditional.
cpu/o3/rename_impl.hh:
    Handle IPR accesses and store conditionals specially.

--HG--
extra : convert_revision : 39debec4fa5341ae8a8ab5650bd12730aeb6c04f