The CI failure for `test_errors_for_bigint_fks_on_integer_pk_table` is
due to the poor regex that extract all ``` `(\w+)` ``` like parts from
the message (`:foreign_key` should be `"old_car_id"`, but `"engines"`):

https://travis-ci.org/rails/rails/jobs/494123455#L1703

I've improved the regex more strictly and have more exercised mismatched
foreign key tests.

Fixes #35294

Fix possible memory leak of ConnectionHandler

refs #35296

Show deprecated message instead of raise exception in `compiled_method_container` method

Since #35212, foreign key feature is supported by all adapters.

[ci skip]

Properly handle cached queries with too many bind parameters

Since #35036, the subclasses of `ActionView::Base` requires
the `compiled_method_container`.
This is incompatible. For example, `web-console` use view class that
subclass of `ActionView::Base`, and does not work it now cause of this.

Actually, since it seems that it is only `ActionView::Base` that
`compiled_method_container` is necessary, modified the condition that
emits a warning.

Allow to pass options to `csp_meta_tag`

Currently `csp_meta_tag` generates `name` attribute only.
However, in libraries like `Material-UI` and `JSS`, expect that the meta tag
that contains the nonce with `property` attribute.

https://material-ui.com/css-in-js/advanced/#how-does-one-implement-csp
https://github.com/cssinjs/jss/blob/master/docs/csp.md

This patch allows `csp_meta_tag` to specify arbitrary options and
allows `nonce` to be passed to those libraries.

AbstractController::Translation#t: dup options

Reword RDBMS note in ActiveRecord basics

Fix Small Typo in Docs [ci skip]

[ci skip]

Deprecate using class level querying methods if the receiver scope regarded as leaked

This deprecates using class level querying methods if the receiver scope
regarded as leaked, since #32380 and #35186 may cause that silently
leaking information when people upgrade the app.

We need deprecation first before making those.

Rails.autoloader and Rails.once_autoloader was just tentative API good
enough for a first patch. Rails.autoloader is singular and does not
convey in its name that there is another autoloader. That might be
confusing, for example if you set a logger and miss traces. On the other
hand, the name `once_autoloader` is very close to being horrible.

Rails.autoloaders.main and Rails.autoloaders.once read better for my
taste, and have a nice symmetry. Also, both "main" and "once" are four
letters long, short and same length.

They are tagged as "rails.main" and "rails.once", respectively.

References #35235.

Address uninitialized constant PostgresqlAdapterTest::ChannelPrefixTest (NameError)

This reverts commit b67d5c6d, reversing
changes made to 2e018361.

Reason: #35186 may cause that silently leaking information when people
upgrade the app.

We need deprecation first before making this.

Fix the `config_for` to always return a NonSymbolAccessDeprecatedHash:

```
$ bundle exec ruby -w -Itest test/subscription_adapter/postgresql_test.rb
Traceback (most recent call last):
	1: from test/subscription_adapter/postgresql_test.rb:8:in `<main>'
test/subscription_adapter/postgresql_test.rb:10:in `<class:PostgresqlAdapterTest>': uninitialized constant PostgresqlAdapterTest::ChannelPrefixTest (NameError)
```

https://travis-ci.org/rails/rails/jobs/493530508

Follow up #35276

Minor changes to deprecation warning message after #35242

Fixes missing method `path_for` when using MirrorService with DiskService as the primary service

Add setter and deprecation for configurations hashes

In chat Sam Saffron asked how to use the setter now that configurations
is no longer a hash and you need to do AR::Base.configurations["test"]=.

Technically you can do `ActiveRecord::Base.configurations = { the hash
}` but I realized the old way throws an error and is unintuitive.

To aid in the transition from hashes to objects this PR makes a few
changes:

1) Re-adds a deprecated hash setter `[]=` that will add a new hash
to the configurations list OR replace an existing hash if that
environment is already present. This won't be supported in future Rails
versions but a good error is important.

2) Changed to throw deprecation warnings on the methods we decided to support
for hash conversion and raise on the methods we don't support.

3) Refactored the setter/getter hash deprecation warnings messages and
rewrote them.

Getters message:

```
DEPRECATION WARNING: `ActiveRecord::Base.configurations` no longer
returns a hash. Methods that act on the hash like `values` are
deprecated and will be removed in Rails 6.1. Use the `configs_for`
method to collect and iterate over the database configurations.
```

Setter message:

```
DEPRECATION WARNING: Setting `ActiveRecord::Base.configurations` with
`[]=` is deprecated. Use `ActiveRecord::Base.configurations=` directly
to set the configurations instead.
```

4) Rewrote the legacy configurations test file to test all the public
methods in the DatabaseConfigurations class.

- If you have hashes inside array, the hashes were getting initialized
  as regular HWIA wereas we want them to be
  NonSymbolAccessDeprecatedHash in order to trigger a deprecation
  warning when keys are accessed with string.

  This patch fixes that by overwriting the `[]=` to to the same
  as what HWIA does (with the difference that we don't call
  `convert_key` to not trigger a deprecation when setting value).

  I also took the liberty to extract `hash.nested_under_indifferent_access`,
  into a separate method to allow subclasses to return whatever
  they want.
  Inheriting HWIA is not common, but I think it's useful for cases
  like this one where we want to preprocess reading and writing values
  in the hash (for deprecation purposes or other reasons).

There is too much to say about it for a CHANGELOG entry, and linking to
the original PR could mislead if there are later changes as already
happened with the gem dependency, so just a one-liner.

For final we'll up to date documentation.

Let Zeitwerk be a dependency of Active Support

Use Dir#children and Dir#each_child in ActiveSupport::Cache::FileStore

Both methods were introduced in Ruby 2.5 and fit this use case very
nicely: listing a directory's entries excluding the "." and ".." nodes.

The private method #exclude_from was removed as it no longer serves
its original purpose.

Adding enque time tracking and logging

Motivation:
  - Currently we have 2 seperate monkey patches in place for tracking
  enqueded time for 2 seperate workers. It seems that activejob could be
  a source of truth for how long an item has been enqued so that we can
  easily use it for consistent monitoring across workers/apps to ensure
  that jobs are running at an acceptable speed.

Changes:
  - Add an enqueded at attribute and serilization tooling.
  - Add a method to get how long a job has been enqueded for.
  - Add a logging item to show how long a job was enqued prior to the
  perform method firing.