0.9.4.85:

0.9.4.85:
	Mostly revert 0.9.4.84, since it doesn't compile at all on modern
        Linux systems (see sbcl-devel message by "Dave" on 2005-09-23):
        * The decision of whether to use personality() should be completely
          a run-time property, not a compile-time one.
        * Change LISP_FEATURE_LINUX cpp conditionals back to LISP_FEATURE_X86
          or remove them entirely (this is in linux-os.c, so LISP_FEATURE_LINUX
          had better be defined; randomization is only enabled on x86 so
          it's pointless to include the code on other platforms)

        Additionally:
        * To solve the problem that 0.9.4.84 was trying to address
          (no <sys/personality.h> on versions of glibc more than three years
          old) define the prototype of personality() in linux-os.c. This
          might not be the optimal solution, but I suppose this isn't the
          right time to experiment...

        The syscall itself is old (goes at least back to kernel 2.0),
        so the system call wrapper should exist even on old versions
        of libc. There should thus be no problems with linking this
        code even on ancient systems.