The attatched moves the remaining guff from gdbarch.{h,c,sh} to

The attatched moves the remaining guff from gdbarch.{h,c,sh} to
arch-utils.{h,c}.  The ``set architecutre'' and ``set endian''
commands (part of the move) were implemented to use add_set_enum_cmd()
so that ``set architecture <tab>'' works.