Update docs for 'parameterize()' [ci skip]

Match evented checker behavior on dir with no exts

Make Template::Resolver always cache

Rename `ActionView::Base#run`

There was a recent change by @tenderlove to Action view which introduced
`ActionView::Base#run` [1].

We ran into an issue with our application because one of the core
concepts in our domain model is a `Run` which is exposed in most of our
views as a helper method, which now conflicts with this new method.

Although this is a public method it is not really meant to be part of
the public API.

In order to discourage public use of this method and to reduce the
chances of this method conflicting with helper methods we can prefix
this method with an underscore, renaming this method to `_run`.

[1] https://github.com/rails/rails/commit/c740ebdaf5

When FileUpdateChecker is passed a directory and given an empty array of
extensions to match on, it will match any extension.

Previously, EventedFileUpdateChecker would never match any files when
given an empty array. This commit makes it EventedFileUpdateChecker
match FileUpdateChecker, and watch all extensions when given an empty
array.

All actionview caches are already cleared at the start of each request
(when Resolver.caching is false) by PerExecutionDigestCacheExpiry, which
calls LookupContext::DetailsKey.clear (which clears all caches).

Because caches are always cleared per-request in dev, we shouldn't need
this extra logic to compare mtimes and conditionally reload templates.

This should make templates slightly faster in development (particularly
multiple renders of the same template)

Properly expand the environment's name in all commands

Since 3777701f, the environment's name is
automatically expanded in console and dbconsole commands.
In order to match the behavior between the commands, fixes it to have the
same behavior of all the commands.

This behavior is defined in `EnvironmentArgument`. Since
`EnvironmentArgument` also defines the environment option, it is reused.

However, since desc was not content that can be used in all comments,
fixed desc to be defined for each command.

Make application work without tmp directory

The tmp directory is added to version control in the newly created
application. This was added in Rails 5.0.0(https://github.com/rails/rails/commit/f06ce4c12a396795a3b2c1812951d9277bcb3a82).

However, applications created before that are not guaranteed to have the
tmp directory. If the tmp directory does not exist, writing to the key file
raise error.

This is a bit incompatible. So I fixed that create the directory before
writing a key.

support slice assignment on SafeBuffer

This was missed in the security fix for local dev. CI doesn't have a tmp
directory in the apps built for testing so these end up failing. This
adds the secret_key_base so we don't need to generate one.

We need to create a secret token in the application so that the travis
build doesn't error when trying to create a file in the tmp directory.

Fixes https://travis-ci.org/rails/rails/jobs/505908163#L6811

This reverts commit 65f2eeaa.

v6.0.0.beta3 release

[skip ci] Rails 5.1+ supports bigint primary key

Follow up #35573

This commit addresses the issue in
https://github.com/rails/rails/issues/35543 by making note of the
growing primary key issue with `create_or_find_by`.

Schema Cache: cache table indexes

Useful to not query for indexes when an application uses schema cache.

Ref https://github.com/rails/rails/pull/35546

Not looking for other contributions like this, but I took the liberty
since I was already working on this.

Update URL in RELEASING_RAILS.md [ci skip]

YAML has been used to serialize the schema cache ever since 2016 with
Rails 5.1: 4c00c6ed

* Update valid link for `signing release tag` from `git-scm` book
* Use `en`(English) instead of `tr`(Turkish) documentation link

The `Row` class is no longer used since d956772b.

Staled `@default_timezone` would cause an error on `reconnect!` after
`disconnect!`.

https://buildkite.com/rails/rails/builds/59495#23be8079-3a4f-4375-9991-0a6f874554f2

Steps to reproduce:

```
% ARCONN=postgresql bin/test test/cases/adapter_test.rb test/cases/base_test.rb -n "/(?:test_attributes_on_dummy_time|test_reconnect_after_a_disconnect)$/" --seed 15849
Using postgresql
Run options: -n "/(?:test_attributes_on_dummy_time|test_reconnect_after_a_disconnect)$/" --seed 15849

# Running:

.
E

Error:
ActiveRecord::AdapterTestWithoutTransaction#test_reconnect_after_a_disconnect:
NoMethodError: undefined method `add_coder' for #<PG::TypeMapAllStrings:0x00007f85ab9dd5b8>
    /Users/kamipo/src/github.com/rails/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:866:in `update_typemap_for_default_timezone'
    /Users/kamipo/src/github.com/rails/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:652:in `exec_no_cache'
    /Users/kamipo/src/github.com/rails/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:636:in `execute_and_clear'
    /Users/kamipo/src/github.com/rails/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:894:in `add_pg_decoders'
    /Users/kamipo/src/github.com/rails/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:744:in `connect'
    /Users/kamipo/src/github.com/rails/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:285:in `rescue in block in reconnect!'
    /Users/kamipo/src/github.com/rails/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:281:in `block in reconnect!'
    /Users/kamipo/.rbenv/versions/2.6.1/lib/ruby/2.6.0/monitor.rb:230:in `mon_synchronize'
    /Users/kamipo/src/github.com/rails/rails/activerecord/lib/active_record/connection_adapters/postgresql_adapter.rb:280:in `reconnect!'
    /Users/kamipo/src/github.com/rails/rails/activerecord/test/cases/adapter_test.rb:465:in `block in <class:AdapterTestWithoutTransaction>'
```

Edit a changelog entry [ci skip]