When a text buffer does not represent a document from a workspace GetOpenDocumentInCurrentContextWithChanges() will return null. Allow for that without a NullReferenceException.

Fixes #24625.

Remove NFW causing delays

Add a comment to make it clear that we don't expect other projects to
still be referencing the project being `Disconnect`ed, and why we're
protecting against it.

Remove a non-fatal Watson report that was triggering frequently and
causing UI delays. We expected that all references to a project would be
removed before the project itself was unloaded, and this report was
added to help us diagnose the rare occasion when that did not occur. It
turns out that it happens quite frequently: when a solution closes, when
a project changes externally and needs to be reloaded, and when a
project is deleted from the solution. We're getting a lot more of these
events than expected, and worse, collecting the Watson data sometimes
causes long pauses in the UI.

We do not have a concrete plan for dealing with the underlying issue,
but the data we've already collected from these reports demonstrates the
scope of the problem and collecting more won't help at this point. Since
the collection itself is causing problems, it's time to just remove it.

Use TLS1.2 for GitHub references

Change our publish script to use TLS1.2 as it downloads assets directly
from GitHub using an https connection

Revert "Enable multicore JIT in the compilers (#23173)"

We've seen crashes that appear to be involved with multicore JIT that
only started soon after multicore JIT was enabled for the compiler
(tracked in #23846). This change disables multicore JIT until we can fix
the root cause of the crashes.

Add telemetry for when projects are created/pushed/etc

Adds 3 telemetry points to see when projects get created, pushed to the
workspace, and have their "LastDesignTimeBuildSucceeded" flag changed.

Fixes internal bug 568001.

The compiler server uses `WriteLine` to generate its output stream,
which uses the correct newlines for the current OS. When splitting
the string back into lines in the MSBuild task, though, the split
was done on Windows newlines.

Fixes #24736 by using `Environment.NewLine` instead of `\r\n` to
pass lines to MSBuild's logger, which expects errors one-per-line.

Report non-fatal errors if projects are removed that are referenced

Keep track of the associated text snapshot when diagnotsics are created.

* Add null check for textSnapshot

Fixes #7364

* Respond to feedback

Changed from return to continue and added a non fatal exception

* respond to feedback

Moved NullTextBufferException to InlineRenameSession and added SourceText.

Notify the remote workspace of working folder paths in the background

Add cast to prevent the dynamic binder from doing the cast

IVsRunningDocumentTable4.GetDocumentData() returns dynamic, and we
were casting it to an interface. This was going through the C#
runtime binder to do so. We don't need that, and an unrelated change in
VS meant that Microsoft.CSharp.dll isn't ngened, so this was far more
expensive than it should be.

@olegtk and @sharwell get credit for the fix.
Co-authored-by: NOleg Tkachenko <olegtk@microsoft.com>
Co-authored-by: NSam Harwell <sam.harwell@microsoft.com>

Add comment.

Add comment.

Switch to getting the text synchronously.

Add comment.

LOC CHECKIN | roslyn dev15.6.x | 20180202

This pulls a .Wait() call off the UI thread in solution load scenarios,
since it's not urgent that we notify the OOP process about the working
folder path. We still ensure the unregister/register ordering is
maintained by ordering the Tasks, and if we have to synchronously shut
down the remote persistent storage, we will still wait. That is a rarer
gesture (it happens on solution rename) and is something we can address
if that's needed.

Merge dev15.5.x to dev15.6.x

Lightbulb header accessibility when selected/focused

Choosing dev15.5.x as the base instead.

Choosing dev15.5.x as the base instead.

Add satellite assemblies to Microsoft.NETCore.Compilers

This also lets the colors change appropriately when the theme is
changed.

Locate implementations for reference assemblies using the GAC

Update optimization data to 2.7.0-beta3-62526-01...

Fix command line build error