Merge dev16.0-preview3 to master

Remove unnecessary test hooks

Disable integration tests with <95% reliability

Bail out for error types from IDE0058 analyzer (unused expression value)

* Enable LinkedFileDiffMergingEditorTests.TestCodeActionPreviewAndApply test

* Enable InteractivePasteCommandhandlerTests.PasteCommandWithOutInteractiveFormat test

* Updated LinkedFileDiffMergingEditorTests with PR feedback
Co-Authored-By: NJoeRobich <joseph.robichaud@microsoft.com>

Support running integration tests in VS 2019

Handle null reference exception during analyzer execution when cancel…

Merge dev16.0-preview3 to master

These tests have an overall pass rate of 84% and 65%, respectively, over
the path 14 days.

See #30544

This test has an overall pass rate of 65% over the past 14 days.

See #33103

Ensure we refresh the project output path when the obj path changes

Fixes #33073

Add IterationDataAttribute for easy test looping

when it happens we will show the info bar and proceed. this is not error recovery but not forcing users to restart VS right away by crashing VS. now user will have time to do what they want and then restart VS

Disable ngen for System.Numerics.Vectors

Updated NuGet package properties

Make the flow analysis based unused value/parameters analyzer more conservative

don't retain fault result in task center if nuget info download failed.

Classify keywords in ForEachVariableStatements as ControlKeywords

If a solution is closed and reopened, still recreate a SolutionId

Fixes VSO Watson [#763828](https://devdiv.visualstudio.com/DevDiv/_workitems/edit/763828)
All the dumps for the watson show that cancellation was requested during analysis, leading to one thread clearing state while other thread faulted.

Do not report unused expression value (IDE0058) for expression body

Work around bug in NamedPipeClientStream.ConnectAsync

Updated version to 3.0.0 beta 4

to retain fault result in task center, we need to provide detail info UI so that user can click the fault task left in the task center, but right now we don't have one and we don't want to just show exception message in message box.

we could think of using RetainAndNotifyFault so that we show exception message in the task center tip, but that would be annoying since most likely it is info user didn't ask for it.

we can add UI later if user ever ask for it. for now, taking simple approach of just removing it from task center once download is done in any way (success, cancelled, failed)

We don't need to await the call to `ConnectAsync` in the async lambda passed to `Task.Run`. Instead we can just have a lambda that returns the same `Task` returned by `ConnectAsync` and `Task.Run` will do the right thing.

LOC CHECKIN | dotnet/roslyn dev16.0-preview3 | 20190131 2

LOC CHECKIN | dotnet/roslyn dev16.0-preview3 | 20190131

Re-enable csharp symbol tests on mono

Merge dev16.0-preview3 to master

Bring EditorFeaturesResources.*.xlf files in line with the current state of EditorFeaturesResources.resx.