Ignore TODO in pkg/analyzer and pkg/analysis_server.

The analyzer team has decided to adopt the convention of using `TODO`
comments to document long term issues that should persist in the
codebase, and `FIXME` comments to document short term issues that need
immediate attention.  They may even consider adding a presubmit hook
to ensure that `FIXME` comments are only used during local
development.

Accordingly, it makes sense to suppress `TODO` comments from being
surfaced to the IDE "problems" view (since there are hundreds of them,
and they're not immediately actionable).  This makes VSCode's
"problems" view much more usable in "tree" mode.

Change-Id: I11a0c59132fb98c1c86fb4adf22d1fdf3b547c80
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/295662
Commit-Queue: Paul Berry <paulberry@google.com>
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>

pkg/analysis_server/analysis_options.yaml

@@ -26,6 +26,7 @@ analyzer:
     non_constant_identifier_names: ignore
     overridden_fields: ignore
     prefer_void_to_null: ignore
+    todo: ignore
 
 linter:
   rules:

pkg/analyzer/analysis_options.yaml

@@ -29,6 +29,7 @@ analyzer:
     implementation_imports: ignore
     library_private_types_in_public_api: ignore
     provide_deprecation_message: ignore
+    todo: ignore
 
   language:
     strict-casts: true

pkg/analyzer/lib/src/workspace/blaze_watcher.dart

@@ -301,7 +301,7 @@ class BlazeFileWatcherService {
   Stream<List<WatchEvent>> get events => _events.stream;
 
   /// Shuts everything down including the watcher isolate.
-  /// FIXME(michalt): Remove this if we really never need to shut down the
+  /// TODO(michalt): Remove this if we really never need to shut down the
   /// isolate.
   void shutdown() {
     if (_isolateHasStarted.isCompleted) {