class.c: descendants must not cause GC until the result array is created

Follow up of 428227472fc6563046d8138aab17f07bef6af753. The previous fix
uses `rb_ary_new_from_values` to create the result array, but it may
trigger the GC.

This second try is to create the result array by `rb_ary_new_capa`
before the second iteration, and assume that `rb_ary_push` does not
trigger GC. This assumption is very fragile, so should be improved in
future.

[Bug #18282] [Feature #14394]

0 files changed, 0 insertions, 0 deletions