fix private attribute warning
Fixes skipping object callback filters

This allows you to skip callbacks that are defined by objects, e.g. for
`ActionController`:

    skip_after_filter MySpecialFilter

Previously this didn't work due to a bug in how Rails compared callbacks
in `Callback#matches?`. When a callback is compiled, if it's an object
filter (i.e. not a method, proc, etc.), `Callback` now defines a method on
`@klass` that is derived from the class name rather than `@callback_id`.
So, when `skip_callback` tries to find the appropriate callback to
remove, `Callback` can regenerate the method name for the filter
object and return the correct value for `Callback#matches?`.
Merge pull request #10090 from vipulnsward/fix_private_warn

fix private attribute warning
has_many through obeys order on through association

fixes #10016
Merge pull request #10087 from neerajdotname/10016

has_many through obeys order on through association
Merge pull request #10034 from benofsky/fix_skipping_object_callback_filters

Fixes skipping object callback filters
stop depending on callbacks
Revert "Merge pull request #10034 from benofsky/fix_skipping_object_callback_filters"

This reverts commit c79c6980647eb76bfa52178711fb04ba7e9d403b, reversing
changes made to ba4c27479add60b783a0e623c8a5d176c1dc9043.

This broke all the tests. See https://travis-ci.org/rails/rails/builds/6061839