Revert "cleanup unused incremental resolution"

pkg/front_end/lib/src/fasta/scanner/token.dart

Index: pkg/front_end/lib/src/fasta/scanner/token.dart
diff --git a/pkg/front_end/lib/src/fasta/scanner/token.dart b/pkg/front_end/lib/src/fasta/scanner/token.dart
index f419056f5cead714a5de7a7174fcd821d231f8b6..e32d2c0149236c320951f757103ff98645195d4e 100644
--- a/pkg/front_end/lib/src/fasta/scanner/token.dart
+++ b/pkg/front_end/lib/src/fasta/scanner/token.dart
@@ -76,6 +76,16 @@ abstract class Token implements analyzer.TokenWithComment {
   @override
   int get end => charEnd;
 
+  @override
+  void applyDelta(int delta) {
+    charOffset += delta;
+    CommentToken token = precedingComments;
+    while (token != null) {
+      token.applyDelta(delta);
+      token = token.next;
+    }
+  }
+
   @override
   analyzer.Token copy() {
     return copyWithoutComments()