Failed TypeScript build:

https://devdiv.visualstudio.com/DevDiv/_git/VS/pullrequest/126057?_a=overview

Use frozen-partial semantics when producing 'accurate' tags.  That way we won't block users as much when copying code.

When a user searches Navigate To, we use a syntax-only cache to find
the items, which we produce without ever using semantics. But once we
actually try to display the item, we are asked (synchronously) for the
glyph and display string, which we do by producing a symbol and then
using that symbol to get the information. If we don't have a compilation
available, this is terribly expensive. As a mitigation for this problem
(tracked in #8260), we can use partial semantics rather than the full
semantics. The glyph and display string shouldn't depend on having a
fully created compilation, and documentation comments being wrong
in the partial file case is something we're willing to live with.

watson shows null exception on DocumentExtensions.GetLanguageService

guarded that method from null exception

Essentially this was just exporting the Suggested-Actions provider for the Roslyn
content type (instead of just the C# and VB types), and making a few codepaths
resilient to getting documents that don't support 'SyntaxTree'.

Add a new internal type DeclaredSymbolInfo which is populated by the syntax trees for NavigateTo to use instead of realizing the compilation/ISymbols. (changeset 1399184)

This change splits the Workspaces layer into two parts, mirroring the Portable/Desktop split that the compilers did. The core parts of the Workspaces layer (managing documents and projects, formatting, some refactoring, code fixes) is kept in the portable subset, with a few non-portable pieces remaining, notably MSBuild support.

This change has a major impact on how MEF now works in Roslyn. Traditional MEF (“MEFv1”) is not portable, and so we must move the Workspaces layer over to using the Microsoft.Composition NuGet package (“MEFv2”) which is. The APIs are distinct in that each has its own namespace, but the concepts are more or less identical. It requires some care though: the workspaces layer is simple in that it only references MEFv2, but higher layers have to reference both versions to use metadata attributes. Exports using metadata attributes from the editor (say, ContentTypeAttribute) must use MEFv1 attributes to export, whereas exports for the workspaces layer must use MEFv2 attributes. The rule is subtle and yet simple, and so a diagnostic is provided which catches any offenses to prevent confusion.

This also has some impact in how we create MEF hosts: if you wish to host just the base workspaces layer, we can use MEFv2 to compose everything. The HostServices implementation (MefV1HostServices) that consumes a MEFv1 ExportProvider. If you’re in Visual Studio, you can use this implementation to get the full set of host services provided in Visual Studio.

Otherwise, most of the changes in here are minor: we react to some APIs that have been moved/renamed in the portable subset we are targeting, and also align our various exception helper utilities with the compiler’s precedent. (changeset 1349276)

Making Document.GetLinkedDocumentIds and Solution.GetDocumentIdsWithFilePath publicly accessible. (changeset 1289255)

Move linked file tracking from the Workspace into the Solution and other small linked file bug fixes. (changeset 1234227)

Track linked files in the workspace and cascade reference searches through symbol definitions at the same position in linked files. (changeset 1233648)

FeaturePacks have changed to become HostServices.
IWorkspaceServiceProvider has become HostWorkspaceServices
ILanguageServiceProvider has become HostLanguageServices

HostWorkspaceServices can be accessed directly from Workspace.Services.
HostLanguageServices can be accessed directly from Project.LanguageServices.

Some of the existing workspace and language services have been made public. (changeset 1226729)