Change feature_index from fake Array to darray

Using a fake (malloc) RArray is not friendly for the garbage
collector. Fake RArray does not have a heap page, so it causes Variable
Width Allocation to crash when we try to implement it on Arrays.

This commit changes feature_index from a RArray to a darray.

1 files changed, 2 insertions, 0 deletions

diff --git a/darray.h b/darray.h
index 6c52b9b1f4..bb8199a98c 100644
--- a/darray.h
+++ b/darray.h
@@ -104,6 +104,8 @@
     rb_darray_make_impl((ptr_to_ary), size, sizeof(**(ptr_to_ary)), \
                          sizeof((*(ptr_to_ary))->data[0]), ruby_xcalloc)
 
+#define rb_darray_data_ptr(ary) ((ary)->data)
+
 // Set the size of the array to zero without freeing the backing memory.
 // Allows reusing the same array.
 //