Update signing cert used for EE.ResultProvider - 16.3 P3

Add tests for RefaHelpers with empty Attributes / empty decls. 

Merge release/dev16.3-preview2 into master

Skip BasicEditAndContinue integration tests that are failing

* Cleanup

* Optimize memory allocation of LCS algorithm

Merge pull request #37594 from jasonmalinowski/add-nullable-annotations-to-speculative-model-creation

Add nullable annotations to speculative model creation and update code for bug found

Merge release/dev16.3-preview1 to master

Update some skip attributes on TypeInferrer tests

Consume the new compiler API for comparing symbols without nullability

Fix using statements to use correct copy of PooledObjects

Fix trailing whitespace and superfluous blank lines in generated GlobalSuppressions.cs

Add an integration test for #37623

* EE: Do not trim comments from expression preceding a quote

Deserialize to VSClientCapabilities

Adds a typing integration test for https://github.com/dotnet/roslyn/pull/37623. Primary bug fixed in the PR: VSO [#957250](https://devdiv.visualstudio.com/DevDiv/_workitems/edit/957250). I verified that the test fails consistently without the fix in #37623 and passes consistently after the fix.

My previous PR #37303 to improve IDE open file analysis performance led to a functional regression where attempting to compute open file diagnostics for a partial type leads to recursive attempt to force complete all partial trees, which in turn attempt force completion of original tree. In presence of cancellation request, this leads to a stack overflow and VS crash. The fix here ensures that we don't attempt partial tree analysis when invoked in context of partial analysis itself.
Fixes VSO [#957250](https://devdiv.visualstudio.com/DevDiv/_workitems/edit/957250) and [#957243](https://devdiv.visualstudio.com/DevDiv/_workitems/edit/957243)
Fixes #37567

I have manually verified the crash before the fix and verified it does not repro after the fix. I am working on adding an integration test for the scenario with a follow-up commit/PR.

 Recognize existing GlobalSuppressions.cs when it has a using directive 

Add back typescript gotodef on the client.

Merge release/dev16.2 to release/dev16.3-preview1

The Microsoft.CodeAnalysis.FlowAnalysis.Utilities assembly which we
consume accidentally made it's copy of the PooledObjects helper public.
That copy has a different namespace, so by using the wrong namespace
we were pulling in that assembly's copy rather than using the copy we
have in our assembly. This causes us to do an early assembly load when
it's absolutely not necessary.

Use expr/block body lambda simplification

Semantic model variable is never used

Fixes https://github.com/dotnet/roslyn/issues/36044

Make Microsoft.CodeAnalysis.Analyzers reference conditional in source-build.