[Bug target/85238] [8 Regression] lto-wrapper: fatal error: simple_object_copy_lto_debug_sections not implemented: Invalid argument on Cygwin

["rguenth at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85238

--- Comment #10 from Richard Biener <rguenth at gcc dot gnu.org> ---
So I guess for darwin we're confused by lto-wrapper.c:debug_objcopy using

  simple_object_read *inobj = simple_object_start_read (infd, inoff,
                                                        "__GNU_LTO",
                                                        &errmsg, &err);
  if (!inobj)
    return NULL;

  off_t off, len;
  if (simple_object_find_section (inobj, ".gnu.debuglto_.debug_info",
                                  &off, &len, &errmsg, &err) != 1)

which won't find the darwin early debug sections anyway and the effect of
the (still correct!) patch is to disable references to the early debug
section in the IL.

So we in additional to that require a target hook that can be queried
from dwarf2out_early_finish () to disable the output of the sections.
Or somehow query the simple-object capability there.