Make sure TLS 1.2 is used to fetch from https://dot.net

* remove random last token from engine.

* put the support back to what it used to, but in different way.

* PR feedback

* added comments on the typing rule.

* PR feedbacks

https://github.com/dotnet/announcements/issues/77 for the change and
where I am stealing this change from.

Disable icacls use on Helix

Remove PR template

We are no longer in ask mode hence no reason to have this around.

The icacls command is failing on Helix hence disabling these tests there
for now

Related to #28836

Use FilePath in VisualStudioWorkspaceImpl.AddDocumentToProjectItems

Bump our .vsixmanifests to say we support installation on Dev16

Merge dev15.9.x to master

Removed redundant sentence fragment.

This seems to be a popular call among analyzers, especially XUnit. It's a
reasonable way to acquire a well-known analyzer type, but analyzers often
don't save the resulting symbol. This causes significant CPU work to be done
repeatedly as XUnit looks for the same symbol over and over, passing in the
same type name each time.

A very small, simple cache seems to solve the problem without requiring any
changes on the XUnit side.

Update SourceLink to 1.0.0-beta-63119-01

Also removes stated support for Dev14, which I'm guessing hasn't
actually worked for quite some time.

* make AbstractObjectBrowserLibraryManager constructor lazier

* PR comments

* readonly and use expression body

Might fix https://github.com/dotnet/roslyn/issues/28782

Fix "Run Code Analysis and Suppress Active Issues" command for CPS pr…

Put completion in 'suggestion' mode when typing a lambda to a method that could be an extension or instance method.

Do not qualify member accesses that appear inside attributes.

Disable leak detection tests on x64

Merge dev15.9.x to master

Looks like RyuJIT change causes our leak detection tests to fail.
Disabling until we find a better pattern to use there.

https://github.com/dotnet/roslyn/issues/28639

Use IHierarchyItemToProjectIdMap service to compare project hierarchies.
Fixes #27002

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

Replace Nonshipping property with IsShipping

Fix InternalsVisibleToCompletionProvider showing unsupported project types

Update Language Feature Status

Add tests.

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

Merge dev15.9.x to master

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