TryGoToDefinition accepted a containingTypeSymbol which was used
to do some specific logic to see if third-party navigation is allowed.
Move that logic to the AbstractGoToDefinitionService and just pass the
result of the logic through.

In order to insert XML doc comment exterior trivia (e.g. /// or '''), we grab the caret position prior to the new line being inserted into the editor and then perform a bit of analysis afterward using that position. However, if there's a selection in the editor and the caret is at the end of that selection, the position will be in an unexpected place in the syntax tree, causing that bit of analysis to fail. So, in this case (and all cases), we use the start of the selection as the position to perform analysis on since that position will be consistent after the new line is inserted.

...to work around machines that already have the old option set.

We were doing so to disable snippets in the interactive window, but it
turns out that it's per-user, rather than per-workspace.

Fixes #5393

MEF based approach had race issue where if aggregator created after source, aggregator will miss events fired before aggregator created.

This change adds a new code action to Features layer Suppression fixer to enable Removing suppressions on diagnostics which are suppressed in source by pragma/SuppressMessageAttribute. Additionally, this change also adds a batch fixer to enable removing suppression on multiple/all diagnostics. This functionality will be consumed by the "Remove suppression(s)" context menu for error list selection.

Avoid repeatedly calling ISyntaxFactsService.IsInInactiveRegion, which calls SyntaxTree.GetToken. GetToken needs to traverse directive trivia to find the token it is
attached to. This results in n ^ 2 traversals of the tree if there are repeated directive before the line to indent. Additionally, when the indenter determines
that it's examining a line inside a disabled region, instead of examining the previous line, it examines the first line preceeding the current line that isn't
inside a disabled region.

Fixes #5394.

* This updates all references to nuget.exe to use the copy in the root.
* This deletes all NuGet.config and NuGet.exe files that are not in the root.
* This removes all references to NuGet.targets (which is obsolete and no longer exists)

Pass CancellationTokens through from Go To Definition. Pass cancellation tokens through type and namespace generation,
since those operations can do large amounts of work.

Pass CancellationTokens through from Go To Definition. Pass cancellation tokens through type and namespace generation,
since those operations can do large amounts of work.

1) Add an API to the suppression fix service to create a baseline for a given project/solution
2) Don't show preview changes dialog for baseline operation.

Fix unit test failures and address PR feedback: IDE diagnostic service now reports source suppressed diagnostics. So add an optional flag to the diagnostic analyzer service APIs to control whether or not to return suppressed diagnostics, and update the test framework to thread this flag.

A fix is forthcoming, but we're seeing a lot of crashes as we dogfood.

Filed https://github.com/dotnet/roslyn/issues/5281 to revert this change.

Add a new suggested action "FixMultipleSuggestedAction" for IDE layer corresponding to FixMultipleCodeAction and FixMultipleContext. Also implement the FixMultipleOccurrencesService to compute and apply a FixMultipleSuggestedAction.

Subsequent change will use this service to fix (suppress) diagnostics selected in the error list.

Put generate-type actions under a higher level "Generate Type" menu item if there are a lot of items in the code actions list.
If there aren't a lot of actions, then inline the items.
Simplify the wording of the "Generate type" actions to make the menu items cleaner.
Provide simple APIs to allow users to create top level menu actions with sub actions.

1. CompilationWithAnalyzers can now report analyzer diagnostics with source suppressions (pragma/SuppressMessageAttribute). This will eventually allow us to surface diagnostics with source suppressions in the error list. Note that the behavior of command line compilers and all the GetDiagnostics APIs is unchanged, only the compiler analyzer will report diagnostics with source suppressions.

2. Add FixAll support for Suppression code fixes. Light bulb suppression fixes now show the "Fix all occurrences" options for Document/Project/Solution. This change adds the basic functionality to bulk suppress diagnostics. This will eventually be consumed for baselining all/selected diagnostics from error list/solution explorer.

3. Simplify the Suppression light bulb menu to remove the option to add a local SuppressMessageAttribute. The only options now are to suppress in source (pragma) or suppressions file (assembly level SuppressMessageAttribute).

...for v1.  Filed #5107 to revive them.

(There are fewer VB tests since VB doesn't have SurroundWith and
Interactive window completion is NYI.)

Bonus: Improve consistency between ```ExecuteCommand``` and
```GetCommandState``` in snippet handler.