gcc build failure

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

/usr/src/external/gpl3/gcc/dist/gcc/combine.c: In function 'int combine_instruct
ions(rtx_insn*, unsigned int)':
/usr/src/external/gpl3/gcc/dist/gcc/combine.c:1310:8: error: 'prev' may be used
uninitialized in this function [-Werror=maybe-uninitialized]
        if ((next = try_combine (insn, prev, NULL, NULL,
        ^~


Looks as though it is set and not equal to zero:

          if (HAVE_cc0
              && JUMP_P (insn)
              && (prev = prev_nonnote_insn (insn)) != 0
              && NONJUMP_INSN_P (prev)
              && sets_cc0_p (PATTERN (prev)))
            {
              if ((next = try_combine (insn, prev, NULL, NULL,
                                       &new_direct_jump_p,
                                       last_combined_insn)) != 0)
                goto retry;

              FOR_EACH_LOG_LINK (nextlinks, prev)
                  if ((next = try_combine (insn, prev, nextlinks->insn,
                                           NULL, &new_direct_jump_p,
                                           last_combined_insn)) != 0)
                    goto retry;
            }