Roll dart_style into the SDK.

This only has two small changes:

- Remove tests of invalid syntax which will no longer be accepted by
  the parser soon: dart-lang/dart_style#1758

- Don't insert a space between `?` and `.` in one corner of the grammar
  because the parser will handle it correctly without a space.

Nothing in the SDK should be affected by this.

Change-Id: If6ef15de45edee9b94afde5f5609b6650647798d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/444371
Commit-Queue: Alexander Thomas <[email protected]>
Auto-Submit: Bob Nystrom <[email protected]>
Reviewed-by: Alexander Thomas <[email protected]>

Author: munificent

DEPS

@@ -126,7 +126,7 @@ vars = {
   #   and land the review.
   #
   # For more details, see https://github.com/dart-lang/sdk/issues/30164.
-  "dart_style_rev": "00b5f3f5256cb179bc340c1e60bb52fd1c2ae1ac", # rolled manually
+  "dart_style_rev": "3499c1ee7a9bc30f3d5b94af932e8f6ac2cffa14", # rolled manually
 
   ### /third_party/pkg dependencies
   # 'tools/rev_sdk_deps.dart' will rev pkg dependencies to their latest; put an