Minor Sconscript edit ... mips decoder changes ... initialize NNPC and output fault...

Minor Sconscript edit ... mips decoder changes ... initialize NNPC and output fault name in simple cpu

SConscript:
    Separate Alpha EIO from syscall building for other architectures
arch/isa_specific.hh:
    change MIPS constant to 34k
arch/mips/isa/decoder.isa:
    Allow sll,ssnop,nop, and ehb to be determined through decoder using
    the different types of default cases
arch/mips/isa/formats/branch.isa:
    Delete debug code
arch/mips/isa/formats/noop.isa:
    add a Nop format
arch/mips/isa_traits.hh:
    use constants instead of enums
arch/mips/process.cc:
    point to the correct header file
cpu/simple/cpu.cc:
    Output the actual fault name
sim/process.cc:
    Inititalize NNPC

--HG--
extra : convert_revision : adb0026dfad25b14c98fb03c98bfe9c681bba6f8