Plus a couple of related ActionPack patches.

Includes two external changes because they're referenced within the ActiveModel test suite.

The ActiveSupport test suite only passes currently if it uses the latest unreleased commits for dalli, and a patch for Builder:
https://github.com/tenderlove/builder/pull/6

Beyond that, all external dependencies (at least, to the extent they’re used by ActiveSupport) are happy, including Nokogiri as of 1.8.0.

Add a test case for #28754

Remove debug print

This debug print was added in 87f5e5e2 for finding the regression caused
by d314646c and the regression has already been fixed in 969339bd.

A part for JSON was splitted from #28416 as #29273 and #29273 has
already been merged.

Closes #28754.
Closes #27588.

[Ryuta Kamizono & Bradley Priest]

Fixes FIXME: rb-inotify 0.99 has been released

[ci skip] Update fedora SQLite3 package name

Remove unused defined association

Remove FK together with column in MySQL

Unlike with other databses, MySQL doesn't let you remove the column
if there's a FK on this column.

For better developer experience we want to remove the FK together with
the column.

Raise on create for singular association when parent is unpersisted

Fix `create_table` with query from relation

Don't require 'unscope' to be the same on both sides of an 'or' relation

Use nullable `id` column instead of a primary key

Remove references to deprecared raise_runtime_errors from documentation, which is always enabled now. Ref: https://github.com/rails/sprockets-rails/commit/655b93bffc6f51b96a7cc097f9010942693bfaae and https://github.com/rails/rails/pull/24070 . Fixes #29483 [ci skip] (#29484)

Add the `<app_root>/test` dir to the `$LOAD_PATH` as a string:

- [Rails <= 5.0](https://github.com/rails/rails/blob/5-0-stable/railties/lib/rails/commands/test.rb#L6) used to add the `<app_root>/test` as a string; this behaviour changed in rails 5.1, it's appending a `Pathname` object

Log subscriber - avoid rescuing certain exceptions

Document setting the delivery_job for ActionMailer [ci skip]

`id` column in `subscribers` was added as a primary key for ignorable in
INSERT. But it caused `NotNullViolation` for oracle-enhanced adapter.

https://github.com/rsim/oracle-enhanced/issues/1357

I changed the column to nullable to address the issue.

[ActiveModel] Improve the performance of mass assignments

Don't map id to primary key in raw_write_attribute

Fix `dump_schema_information` with empty versions

Add test cases for #28274

Allow mailers to configure their delivery job

The `raw_write_attribute` method is used to update a record's attributes
to reflect the new state of the database in `update_columns`. The hash
provided to `update_columns` is turned into an UPDATE query directly,
which means passing an `id` key results in an update to the `id` column,
even if the model uses a different attribute as its primary key. When
updating the record, we don't want to apply the `id` column change to
the primary key attribute, since that's not what happened in the query.

Without the code to handle this case, `write_attribute_with_type_cast`
no longer contains any logic shared between `raw_write_attribute` and
`write_attribute`, so we can inline the code into those two methods.

Fixes #29460.

Update `working with javascript` readme to support rails-ujs behaviour. [ci skip]

Setting delivery_job on a mailer class will cause MessageDelivery to use
the specified job instead of ActionMailer::DeliveryJob:

    class MyMailer < ApplicationMailer
      self.delivery_job = MyCustomDeliveryJob

      ...
    end