gc: use single allocation for prot_array.

* gc.c (prot_array): Add self pointer; arr member
becomes flexible array.
(prot_array_mark): We now check the handle itself for
null, because the whole thing is freed.
(prot_array_free): Function removed.
(prot_array_ops): Wire cobj_destroy_free_op in place
of prot_array_free. This fixes a memory leak because
prot_array_free was not freeing the handle, only
the array.
(gc_prot_array_alloc): Fix to allocate everything
in one swoop and store the self-pointer in the
named member rather than arr[-1]. The self argument
is not required; we drop it. The size argument cannot
be anywhere near INT_PTR_MAX, because such an array
wouldn't fit into virtual memory, so it is always
safe to add a small value to the size.
(prot_array_free): Obtain the self-pointer, and
free the handle, replacing it with a null pointer.

* gc.h (gc_prot_array_alloc): Declaration updated.

* lib.c (ssort_vec): Don't pass self to gc_prot_array_alloc.

* lib.h (container): New macro.

1 files changed, 1 insertions, 1 deletions

diff --git a/gc.h b/gc.h
index 58d057db..e89e695a 100644
--- a/gc.h
+++ b/gc.h
@@ -87,5 +87,5 @@ INLINE void gc_stack_check(void)
     gc_stack_overflow();
 }
 
-val *gc_prot_array_alloc(cnum size, val self);
+val *gc_prot_array_alloc(cnum size);
 void gc_prot_array_free(val *);