[Bug libgcc/71744] Concurrently throwing exceptions is not scalable

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71744

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
This cache:
/* The unseen_objects list contains objects that have been registered
   but not yet categorized in any way.  The seen_objects list has had
   its pc_begin and count fields initialized at minimum, and is sorted
   by decreasing value of pc_begin.  */
static struct object *unseen_objects;
static struct object *seen_objects

In "unwind-dw2-fde.c".

So there is no global lock by the way, just around the area which accesses the
above two objects.