Slow lang_insert_orphan

[H. J. Lu]

When we have many orphaned sections, lang_insert_orphan spends lots
of time in

/* Unlink the section.  */
for (pps = &output_bfd->sections; *pps != snew; pps = &(*pps)->next)
  continue;

It is the case of 64K section ld test. Use a doubly linked list
for section may help. But it will add a pointer to bfd_section. Should
I give a try?


H.J.