remove deprecated `assert_present` and `assert_blank`.
Remove deprecated `:distinct` option from `Relation#count`.
Merge pull request #11226 from senny/remove_deprecated_distinct_option

Remove deprecated `:distinct` option from `Relation#count`.
Merge pull request #11224 from senny/remove_assert_blank_and_assert_present

remove deprecated `assert_present` and `assert_blank`.
remove deprecated `BufferedLogger`.
remove auto-explain-config deprecation warning
Remove `FormBuilder` deprecation warning about block argument and associated tests
Merge pull request #11227 from vipulnsward/form_builder

Remove `FormBuilder` deprecation warning about block argument and tests
remove deprecated `ActiveRecord::Base#connection` method.
the data structure used to store attribute aliases should not be exposed
Add missing require

Commit cfa35c55bb38b27af305ad21408e181bc3cd739e removed the
buffered_logger from AS, which required the logger file. Now we need to
add the proper require here.
we don't need to to_s the column
stop exposing the underlying alias datastructure
Remove deprecation messages about protected_attributes and rails-observers
Removed deprecated options for assocations

Deprecated options `delete_sql`, `insert_sql`, `finder_sql` and `counter_sql`
have been deleted.
build an AST rather than slapping strings together
Merge pull request #11222 from neerajdotname/removed-deprecation-for-sql

Removed deprecated options for assocations
only deal with strings internally
make the identity type a singleton to save on object creation
avoid intermediate zipped array