Use `silence` instead of `quietly` to silence the `CheckPending` middleware.

`Kernel.quietly` silences `STDOUT` and `STDERR`, which is useless if
the logger is writing to a file, while `AS::Logger#silence` swaps the
logger level to `ERROR`.

Related to #8820 and #8052.
Merge pull request #9087 from lucasmazza/silence-migration-checks

Use `silence` instead of `quietly` to silence the `CheckPending` middleware.
Fix cases where delete_records on a has_many association caused errors
because of an ambiguous column name. This happened if the association
model had a default scope that referenced a third table, and the third
table also referenced the original table (with an identical
foreign_key).

Mysql requires that ambiguous columns are deambiguated by using the full
table.column syntax. Postgresql and Sqlite use a different syntax for
updates altogether (and don't tolerate table.name syntax), so the fix
requires always including the full table.column and discarding it later
for Sqlite and Postgresql.
Fix typo: adaptors => adapters [ci skip]
Prevent Relation#merge from collapsing wheres on the RHS

This caused a bug with the new associations implementation, because now
association conditions are represented as Arel nodes internally right up
to when the whole thing gets turned to SQL.

In Rails 3.2, association conditions get turned to raw SQL early on,
which prevents Relation#merge from interfering.

The current implementation was buggy when a default_scope existed on the
target model, since we would basically end up doing:

  default_scope.merge(association_scope)

If default_scope contained a where(foo: 'a') and association_scope
contained a where(foo: 'b').where(foo: 'c') then the merger would see
that the same column is representated on both sides of the merge and
collapse the wheres to all but the last: where(foo: 'c')

Now, the RHS of the merge is left alone.

Fixes #8990
add fetch to CookieJar