Alot of changes to push towards ISA independence. Highlights are renaming of the...

Alot of changes to push towards ISA independence. Highlights are renaming of the isa_desc files, movement of byte_swap.hh into sim, and the creation of arch/isa_traits.hh

SConscript:
    Moved some files out of targetarch. The either no longer need to be there, never needed to be there, or should be referred to directly in arch/alpha due to there strictly alpha content.
arch/alpha/isa_traits.hh:
    Added alpha's endianness to it's isa_traits.hh
arch/mips/isa_traits.hh:
    Added MIPS endianness to it's isa_traits.hh
arch/sparc/isa_traits.hh:
    Added SPARCs endianess to it's isa_traits.hh
build/SConstruct:
    Added MIPS as a valid architecture
cpu/exec_context.hh:
    Included arch/isa_traits.hh to bring in the endianness of the system.
cpu/o3/alpha_cpu.hh:
    Included arch/isa_traits.hh to bring in the systems endianness, and removed the hardcoding of little endianness
cpu/o3/fetch_impl.hh:
kern/freebsd/freebsd_system.cc:
    Included arch/isa_traits.hh to bring in the systems endianness, and removed the hardcoding to little endianness.
sim/system.cc:
    Included arch/isa_traits.hh to bring in the systems endianness, and removed the hardcoding to little endian.

--HG--
extra : convert_revision : b1ab34b7569db531cd1c74f273b24222e63f9007