* Add AB tests for code cleanup
revert the text change of Code_cleanup_is_not_configured, as the new text is not translated
Only SettingIsAlreadyUpdatedByExperiment to ture for Group B; always show gold bar if user setting is changed in AB test

Merge dev15.8.x to dev15.9.x

Fix windows_loc_changes leg

When I created the windows_loc_changes job for Jenkins I thought the
`GIT_BRANCH` environment variable contained the name of the branch a
change would be merged into. Instead, it contains the name of the
"head" branch, which is not helpful for this purpose. I have not yet
been able to identify an environment variable that has the name of the
"base" branch instead.

As a workaround, this commit updates netci.groovy to capture the branch
name when the job is generated.

Add a Jenkins leg to check for loc changes

Merge dev15.8.x to dev15.9.x

Fix InternalsVisibleToCompletionProvider showing unsupported project types

Add a Jenkins leg to check for loc changes. Once we're past the loc
freeze date for a release branch we want to block any PRs that modify
.xlf files.

Note that we *do* need a way to let updates from the Loc team through,
but that is not addressed by this change.

Merge dev15.8.x to dev15.9.x

Merge dev15.8.x to dev15.9.x

When we enabled pointer_element_access to work on fixed sized buffers
regardless of the movability of the receiver of the buffer access, we
did not repair the safety rules to prevent leaking a pointer to a
moveable variable back into the language.

This change adds a new rule, which makes the movability of a
pointer_element_access on a fixed size buffer dependent on the
movability of its receiver. This should require the use of a `fixed`
statement to prevent safety holes.

Fixes #28476

Merge dev15.8.x to dev15.9.x

Merge dev15.8.x to dev15.9.x

Set VSSDKTargetPlatformRegRootSuffix for Roslyn.csproj

Use a 75 minute test timeout on CI

Closes #28410

Merge dev15.8.x to dev15.9.x

* Add telemetry for infobar selections

* Add telemetry for Tools options settings related to code cleanup

* Fix telemetry logging

* Add telemetry when infobar is displayed

* added log that can be used for perf investigation

* Respond to feedback

* Fix merge conflicts

* Respond to feedback

* Move logger block

* Move logger block

* Respond to feedback

* Respond to feedback

Don't ensure we have a FileChangeTracker until we actually read the file

Merge dev15.8.x to dev15.9.x

Merge dev15.8.x to dev15.9.x

Report progress for the actions we're talking while doing code-cleanup.

Fix NRE when handling multiline documentation comments in C#

* Fix discard symbol for declaration pattern

* Remove unnecessary cast

basically this Solution/DocumentBranch strongly holding onto next State causes
old roslyn snapshot to make every snapshot after it to stay in memory.

or worse, it causes a lot of forked solution to be left alive in memory until
certain snapshot goes away.

we will first try to simply get rid of this optimization and see whether we can observe
impact on RPS.

if it somehow shows up, we will change it to weak reference rather than strongly hold onto it

Use default constant value for synthesized local reference for LockTa…

* use correct line ending

* ported https://github.com/mono/monodevelop/pull/5335/files

Fix generating types into an existing file

* Break 'remove unnecessary this/me' into it's own analyzer+codefixer.

* Share code.

* Simplify.

* Simplify code.

* Simplify.

* Add comment.

* Inline method.

* Revert accessibility

* Update tests.

* Move tests.

* Make all edits at once.

* Move files.

* Simplify

make code cleanup run in-proc

add PerformAdditionalCodeCleanupDuringFormattingCheckBox

This .EnsureSubscription() was very premature.

Updated RoslynNuGetMoniker version for 15.9

This version includes now required `signers` entry to Willow package manifest.