[Bug pch/61250] Random pch failures on x86_64-apple-darwin1(3|4).

[howarth at bromo dot med.uc.edu]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61250

--- Comment #13 from howarth at bromo dot med.uc.edu ---
The offending line appears to be at...

static const struct line_map*
linemap_macro_map_lookup (struct line_maps *set, source_location line)
{
  unsigned int md, mn, mx;
  const struct line_map *cached, *result;

  if (IS_ADHOC_LOC (line))
    line = set->location_adhoc_data_map.data[line & MAX_SOURCE_LOCATION].locus;

  linemap_assert (line >= LINEMAPS_MACRO_LOWEST_LOCATION (set));  <=====