Be resilient to having a project that doesn't know about ArgumentNullException or ArgumentException

Fixes #19171
Fixes #19174
Fixes #19173

TypingHelpDirectiveWorks()   - https://github.com/dotnet/roslyn/issues/19232
WorkspacesNetCore.ProjectReference() -  https://github.com/dotnet/roslyn/issues/19231

Ensure that we get a well formed child IOperation tree even for bound…

Add type inference support for tuples.

Enable multiline regex mode for "test <whatever> please"

Include DSRN in toolset package

Merge dev15.3-preview1 to master

Related to #19223

Consider name when matching hierarchy items to projects

Batch 'designer attribute argument' changes.

Add a couple of tests

This means you can write a comment and then do the line by itself in
one GitHub comment. Otherwise it's requiring you have exactly one
per comment which is annoying.

Add arglist test and revert changes to BoundByRefArgumentWithCopyBack as it is never exposed in the operation tree

Fixes #18859

Actually keep track of the task we've kicked off to flush all writes to disk.

The VS SDK team provided us with an updated NuGet that has better error
diagnostics during install / uninstall.  Going to change our VSI tests
to begin using build based deployment again for VSIX until they can get
the diagnostics that they need.  Once they have them will flip it back.

The VS SDK team is interested in tracking down the deployment errors
that we are seeing when deploying as a part of build.  This change adds
an option to make it easy to excercise that code path in builds.

Going to use this option to quickly toggle to the build based deployment
in order to mass test their fixes.

Our Test.cmd script and Microbuild test running got messed up during the
recent SDK change.  A series of conflicts were just merged incorrectly.

This moves the logic for testVsiNetCore into the BuildAndTest.proj file.
This matches the logic behavior for all of our other test runs.  It also
avoids us further complicating the necessary command line for calling
the BuildAndTest.proj file.

Eventually though want to move all of the test logic into a Powershell
file.  The MSBuild file at this point is approaching the complexity of a
full script but lacking the flexibility.  Should just convert it to a
script and move on.

The example ruleset provided contains some syntax errors, so copy/pasting wholesale somewhere can result in build errors when including it.

There was also a minor typo I found later in the file while reading through.