Use rb_darray_insert_without_gc for heap_pages darray

rb_darray_insert could trigger a GC, which would cause problems if it
freed pages while a new page was being inserted.

For example, the following script fails:

    GC.stress = true
    GC.auto_compact = :empty

    10.times do
      GC.verify_compaction_references(expand_heap: true, toward: :empty)
    end

It errors out with:

    'GC.verify_compaction_references': malloc: possible integer overflow (8*18446744073709551603) (ArgumentError)

1 files changed, 1 insertions, 1 deletions

diff --git a/gc/default/default.c b/gc/default/default.c
index b0267cc48c..94828be55d 100644
--- a/gc/default/default.c
+++ b/gc/default/default.c
@@ -1961,7 +1961,7 @@ heap_page_allocate(rb_objspace_t *objspace)
         }
     }
 
-    rb_darray_insert(&objspace->heap_pages.sorted, hi, page);
+    rb_darray_insert_without_gc(&objspace->heap_pages.sorted, hi, page);
 
     if (heap_pages_lomem == 0 || heap_pages_lomem > start) heap_pages_lomem = start;
     if (heap_pages_himem < end) heap_pages_himem = end;