Previously, this used `Array#-`, which would remove all queries that matches the
query text in the original set.

However, sometimes we have a problem with parameterised queries, where the query
text is identical both times, so we'd run a query N times instead of once, and
it would be hidden from the output.

Replace the logic to only remove a given query N times from the actual log,
where N is the number of times it appears in the expected log.

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/40295

This changes Ci::Pipeline#latest_builds_with_artifacts so it returns an
Array instead of a relation. Whenever we use this data we do so in two
steps:

1. Count the number of rows
2. If this number is greater than 0, iterate over the rows

By returning an Array instead we only execute 1 query of which the total
time/work is less than running either just a COUNT(*) or both queries
(in the worst case).

On GitLab.com this change should save us a few milliseconds per request
to ProjectsController#show.

After installing a new gem, batch-loader, a construct can be used to
queue data to be fetched in bulk. The gem was also introduced in both
gitlab-org/gitlab-ce!14680 and gitlab-org/gitlab-ce!14846, but those mrs
are not merged yet.

For the generation of diffs, both the old blob and the new blob need to
be loaded. This for every file in the diff, too. Now we collect all
these so we do 1 fetch. Three `.allow_n_plus_1_calls` have been removed,
which I expect to be valid, but this needs to be confirmed by a full CI
run.

Possibly closes:
- https://gitlab.com/gitlab-org/gitlab-ce/issues/37445
- https://gitlab.com/gitlab-org/gitlab-ce/issues/37599
- https://gitlab.com/gitlab-org/gitlab-ce/issues/37431

since `Rails.application.routes.url_helpers` creates a new anonymous module every time it's called

In !15082, we changed the behavior of the middleware to call
`Rails.application.routes.recognize_path` whenever a new route arrived.
However, this can be a CPU-intensive task because Rails needs to allocate
memory and compile 850+ different regular expressions, which are complicated
in GitLab.

As a short-term fix, we can do a lightweight string match before
we do the heavier comparison.

Closes #40185, gitlab-com/infrastructure#3240

Fix https://gitlab.com/gitlab-org/gitlab-ce/issues/39821

/<namespace>/<project>/commmits/master

When a project is using hashed storage, the repositories and
attachments wouldn't be saved on disk using the `full_path`. So the
migration would not do anything.

However: best to just skip moving when hashed storage is enabled.

This adds various foreign keys and indexes to the "merge_requests" table
as outlined in https://gitlab.com/gitlab-org/gitlab-ce/issues/31825.

Fixes https://gitlab.com/gitlab-org/gitlab-ce/issues/31825

Sets `autocomplete=off` to issuable filtered serarch.

Conflicts used to take a `Repository` and pass that to
`Gitlab::Highlight.highlight`, which would call `#gitattribute` on the
repository. Now they use a `Gitlab::Git::Repository`, which didn't have that
method defined - but defining it on `Gitlab::Git::Repository` does make it
available on `Repository` through `method_missing`, so we can do that and both
cases will work.