Implement _SameResolutionValidator as AstComparator.

pkg/analyzer/test/generated/incremental_resolver_test.dart

Index: pkg/analyzer/test/generated/incremental_resolver_test.dart
diff --git a/pkg/analyzer/test/generated/incremental_resolver_test.dart b/pkg/analyzer/test/generated/incremental_resolver_test.dart
index 518f8c8ae538e26e898e4ce4aab69258ad93aa08..03309ddd504a80e9ed2fc84f0b018a4669028c53 100644
--- a/pkg/analyzer/test/generated/incremental_resolver_test.dart
+++ b/pkg/analyzer/test/generated/incremental_resolver_test.dart
@@ -3556,10 +3556,13 @@ class B {
   }
 
   static void _shiftTokens(Token token, int afterOffset, int delta) {
-    while (token.type != TokenType.EOF) {
-      if (token.offset >= afterOffset) {
+    while (true) {
+      if (token.offset > afterOffset) {
         token.applyDelta(delta);
       }
+      if (token.type == TokenType.EOF) {
+        break;
+      }
       token = token.next;
     }
   }