last changes before big merge

last changes before big merge

arch/alpha/isa_traits.hh:
arch/sparc/isa_traits.hh:
    add nnpc for compiling purposes in exec_context setNextNPC function
cpu/exec_context.hh:
    set NNPC function
cpu/simple/cpu.cc:
    use NNPC in determining what PC we are using

--HG--
extra : convert_revision : e810cfbc5dc31879b20d2cc40bf9871613203532