These are using `remove_column` directly, not used `t` in
`change_table`.

Like other Basics and Overview guides.

Fix in ASt guide [ci skip]

[ci skip] Inherit ActiveRecord::Base in example codes

Currently, generation of guide is an error in `5_2_release_notes.html`.

```
$ bunele exec rake guides:generate:html
Generating 5_2_release_notes.md as 5_2_release_notes.html
rails/guides/rails_guides/markdown.rb:44:in `dom_id': undefined method `[]' for nil:NilClass (NoMethodError)
	from rails/guides/rails_guides/markdown.rb:106:in `block (2 levels) in generate_structure'
```

It seems that it is an error because there are multiple
`active-storage` anchors.

Since Active Storage is a Major feature, it is unnecessary to show
CHANGELOGs, so remove from `Incompatibilities` section.

[ci skip] Add missing **DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.**

[ci skip] update link

[ci skip] Update guide index for active storage

`dump_schema_cache` fills `schema_cache` even if the test that modifies
the schema has properly cleared the schema cache.

Fixes #31463.

ActiveStorage Guide

`make_tmpname` was removed by https://github.com/ruby/ruby/commit/25d56ea7b7b52dc81af30c92a9a0e2d2dab6ff27.
In this case, we want a file name, not a `File`. So cannot use `Tempfile`.

Fixes #31458

Suppress `warning: BigDecimal.new is deprecated`

`BigDecimal.new` has been deprecated in BigDecimal 1.3.3
 which will be a default for Ruby 2.5.

Refer
https://github.com/ruby/bigdecimal/commit/533737338db915b00dc7168c3602e4b462b23503

* This commit has been made as follows:

```
cd rails
git grep -l BigDecimal.new | grep -v guides/source/5_0_release_notes.md | grep -v activesupport/test/xml_mini_test.rb | xargs sed -i -e "s/BigDecimal.new/BigDecimal/g"
```
- `activesupport/test/xml_mini_test.rb`
Editmanually to remove `.new` and `::`

- guides/source/5_0_release_notes.md
This is a Rails 5.0 release notes.

* The `DEFAULT_ERROR_HANDLER` constant in
  `ActiveSupport::Cache::RedisCacheStore` contained references
  to an undefined argument `e`, which is supposed to refer
  to the `exception` parameter.
* Update the default error handler proc to correctly reference
  the `exception` parameter.

Provide instant feedback when booting Rails

Suppress `warning: BigDecimal.new is deprecated` in Active Model

Address `warning: instance variable @hash_digest_class not initialized`

Suppress expected exceptions by `report_on_exception` = `false` in mysql2 test

Follow up #31428 to address similar exceptions with mysql2 adapter

`BigDecimal.new` has been deprecated in BigDecimal 1.3.3
 which will be a default for Ruby 2.5.

Refer ruby/bigdecimal@5337373

* This commit has been made as follows:

```ruby
$ cd activemodel/
$ git grep -l BigDecimal.new | grep \.rb | xargs sed -i -e "s/BigDecimal.new/BigDecimal/g"
```

* This commit has been tested with these Ruby versions:

```
ruby 2.5.0dev (2017-12-15 trunk 61262) [x86_64-linux]
ruby 2.4.2p198 (2017-09-14 revision 59899) [x86_64-linux]
ruby 2.3.5p376 (2017-09-14 revision 59905) [x86_64-linux]
ruby 2.2.8p477 (2017-09-14 revision 59906) [x86_64-linux]
```

```ruby
/path/to/rails/activesupport/lib/active_support/digest.rb:7:
warning: instance variable @hash_digest_class not initialized
``

Initial support for running Rails on FIPS-certified systems

Log the original call site for an ActiveRecord query

Follow up of #31432.

I've noticed during pair/mob programming sessions with peers that
despite the speed boosts provided by Bootsnap and Spring, there is a
noticeable latency between firing a bin/rails server command and any
feedback being provided to the console. Depending on the size of the
application this lack of feedback can make it seem like something is
wrong when Rails is simply busy initializing.

This change may seem gratuitous but by just printing one line to STDOUT
we're giving a clear signal to the Rails user that their command has
been received and that Rails is indeed booting. It almost imperciptibly
makes Rails feel more responsive.

Sure the code doesn't look very fancy but there's no other appropriate
place I could think of putting it than boot.rb.

Compare these two GIFs of booting without and with this change:

Before:
![Without Boot Feedback](https://user-images.githubusercontent.com/65950/33964140-721041fc-e025-11e7-9b25-9d839ce92977.gif)

After:
![With Boot Feedback](https://user-images.githubusercontent.com/65950/33964151-79e12f86-e025-11e7-93e9-7a75c70d408f.gif)

This new ActiveRecord configuration option allows you to easily
pinpoint what line of application code is triggering SQL queries in the
development log by appending below each SQL statement log the line of
Ruby code that triggered it.

It’s useful with N+1 issues, and to locate stray queries.

By default this new option ignores Rails and Ruby code in order to
surface only callers from your application Ruby code or your gems.

It is enabled on newly generated Rails 5.2 applications and can be
enabled on existing Rails applications:

```ruby
Rails.application.configure do
  # ...
  config.active_record.verbose_query_logs = true
end
```

The `rails app:upgrade` task will also add it to
`config/development.rb`.

This feature purposely avoids coupling with
ActiveSupport::BacktraceCleaner since ActiveRecord can be used without
ActiveRecord. This decision can be reverted in the future to allow more
configurable backtraces (the exclusion of gem callers for example).

The v4.3.1 has already released that includes Redis 4.0 support.
https://github.com/resque/resque-scheduler/blob/master/CHANGELOG.md#431---2017-11-20

Preserve original method visibility when deprecating a method

Suppress `warning: BigDecimal.new is deprecated` in activerecord

`BigDecimal.new` has been deprecated in BigDecimal 1.3.3
 which will be a default for Ruby 2.5.

Refer https://github.com/ruby/bigdecimal/commit/533737338db915b00dc7168c3602e4b462b23503

```
$ cd rails/activerecord/
$ git grep -l BigDecimal.new | grep \.rb | xargs sed -i -e "s/BigDecimal.new/BigDecimal/g"
```

- Changes made only to Active Record. Will apply the same change to
other module once this commit is merged.

- The following deprecation has not been addressed because it has been
reported at `ActiveRecord::Result.new`. `ActiveRecord::Result.ancestors`
did not show `BigDecimal`.

* Not addressed

```ruby
/path/to/rails/activerecord/lib/active_record/connection_adapters/mysql/database_statements.rb:34:
warning: BigDecimal.new is deprecated
```

* database_statements.rb:34

```ruby
ActiveRecord::Result.new(result.fields, result.to_a) if result
```

* ActiveRecord::Result.ancestors

```ruby
[ActiveRecord::Result,
 Enumerable,
 ActiveSupport::ToJsonWithActiveSupportEncoder,
 Object,
 Metaclass::ObjectMethods,
 Mocha::ObjectMethods,
 PP::ObjectMixin,
 ActiveSupport::Dependencies::Loadable,
 ActiveSupport::Tryable,
 JSON::Ext::Generator::GeneratorMethods::Object,
 Kernel,
 BasicObject]
```

This commit has been tested with these Ruby and BigDecimal versions

- ruby 2.5 and bigdecimal 1.3.3

```
$ ruby -v
ruby 2.5.0dev (2017-12-14 trunk 61217) [x86_64-linux]
$ gem list |grep bigdecimal
bigdecimal (default: 1.3.3, default: 1.3.2)
```

- ruby 2.4 and bigdecimal 1.3.0

```
$ ruby -v
ruby 2.4.2p198 (2017-09-14 revision 59899) [x86_64-linux-gnu]
$ gem list |grep bigdecimal
bigdecimal (default: 1.3.0)
```

- ruby 2.3 and bigdecimal 1.2.8

```
$ ruby -v
ruby 2.3.5p376 (2017-09-14 revision 59905) [x86_64-linux]
$ gem list |grep -i bigdecimal
bigdecimal (1.2.8)
```

- ruby 2.2 and bigdecimal 1.2.6
```
$ ruby -v
ruby 2.2.8p477 (2017-09-14 revision 59906) [x86_64-linux]
$ gem list |grep bigdecimal
bigdecimal (1.2.6)
```

This commit fixes `deprecate` so that it preserves method visibility (like it
did previously when it was utilizing `alias_method_chain`).

When Module#prepend replaced alias_method_chain in a982a42d it caused deprecated
methods to always become public.

`alias_method_chain` had this bit of code:
https://github.com/rails/rails/blob/v5.0.6/activesupport/lib/active_support/core_ext/module/aliasing.rb#L40-L47
which preserved method visibility.

Without this fix, a workaround would be:

```ruby
class C8
  private

  def new_method
  end

  def old_method
  end
  deprecate :old_method, :new_method
  # workaround:
  instance_method(:old_method).owner.send(:private, :old_method)
end
```

Because the visibility needs to be fixed on the Module prepended by
MethodWrapper.