anchor.diff:  import 'package:analyzer/src/generated/source_io.dart';
   import 'package:analyzer/src/summary/format.dart';
   import 'package:analyzer/src/summary/idl.dart';
  -import 'package:analyzer/src/summary/prelink.dart';
  +import 'package:analyzer/src/summary/link.dart';
   import 'package:analyzer/src/summary/summarize_ast.dart';
   import 'package:kernel/analyzer/loader.dart';
   import 'package:kernel/kernel.dart';
  
positive.code:   scanTotalChars = 0;
    parseTimer = new Stopwatch();
    unlinkedSummarizeTimer = new Stopwatch();
    for (var source in files) {
      unlinkedSummarize(source);
    }
  
    if (old != scanTotalChars) print('input size changed? ${old} chars');
    report("scan", scanTimer.elapsedMicroseconds);
  
negative.code:   scanTotalChars = 0;
    parseTimer = new Stopwatch();
    unlinkedSummarizeTimer = new Stopwatch();
    var unlinkedSummaries = generateUnlinkedSummaries(files);
    prelinkSummaryTimer = new Stopwatch();
    prelinkSummaries(files, unlinkedSummaries);
  
    if (old != scanTotalChars) print('input size changed? ${old} chars');
    report("scan", scanTimer.elapsedMicroseconds);
  