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

Fix InternalsVisibleToCompletionProvider showing unsupported project types

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.

Fallback navigate to

Merge dev15.8-preview4 to dev15.8.x

Merge dev15.8-preview4 to dev15.8.x