* sysdeps/unix/sysv/linux/alpha/init-first.h,
sysdeps/unix/sysv/linux/m68k/init-first.h,
sysdeps/unix/sysv/linux/i386/init-first.h: New files.
* sysdeps/unix/sysv/linux/init-first.c: Use platform-dependent
init-first.h to make abstract machine dependent parts of
initialization.