Follow up on https://dart-review.googlesource.com/c/sdk/+/142705 to fix the assertion in the new completions in FieldDeclarations

Change-Id: Id50663401c5dff67cb69fd30aece229f5c1f6617
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/142883
Commit-Queue: Jaime Wren <[email protected]>
Commit-Queue: Brian Wilkerson <[email protected]>
Auto-Submit: Jaime Wren <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: jwren

pkg/analysis_server/test/services/completion/dart/imported_reference_contributor_test.dart

@@ -1978,8 +1978,10 @@ class B extends ^
     addSource('/home/test/lib/a.dart', 'class A { }');
     addTestSource('''
         import 'a.dart';
-        // comment
-        class C {^ foo;} ''');
+        class C {
+          // comment
+          ^ foo;
+        } ''');
 
     await computeSuggestions();
     assertSuggestClass('A');
@@ -1992,8 +1994,10 @@ class B extends ^
     addSource('/home/test/lib/a.dart', 'class A { }');
     addTestSource('''
         import 'a.dart';
-        /* comment */
-        class C {^ foo;} ''');
+        class C {
+          /* comment */
+          ^ foo;
+        } ''');
 
     await computeSuggestions();
     assertSuggestClass('A');
@@ -2006,8 +2010,10 @@ class B extends ^
     addSource('/home/test/lib/a.dart', 'class A { }');
     addTestSource('''
         import 'a.dart';
-        /// some dartdoc
-        class C {^ foo;} ''');
+        class C {
+          /// some dartdoc
+          ^ foo;
+        } ''');
 
     await computeSuggestions();
     assertSuggestClass('A');