anchor.diff:  // Version of DartFuzz. Increase this each time changes are made
   // to preserve the property that a given version of DartFuzz yields
   // the same fuzzed program for a deterministic random seed.
  -const String version = '1.20';
  +const String version = '1.21';
   
   // Restriction on statements and expressions.
   const int stmtLength = 2;
  
positive.code:         return emitScope(depth);
        case 12:
          return emitTryCatch(depth);
        default:
          return emitAssign();
      }
  
negative.code:         break;
        case 2:
          {
            final int i = localVars.length;
            emit('for (int $localName$i ');
            // For-loop (induction, list, set).
            switch (rand.nextInt(3)) {
  