Optimize more megamorphic dispatch sites

pkg/analyzer/lib/src/task/driver.dart

Index: pkg/analyzer/lib/src/task/driver.dart
diff --git a/pkg/analyzer/lib/src/task/driver.dart b/pkg/analyzer/lib/src/task/driver.dart
index b0cabae2d60557fd9000a3145e5e44e1b40627b1..70ebe3ba5a5e3d01c063baacdb98099b111ebef2 100644
--- a/pkg/analyzer/lib/src/task/driver.dart
+++ b/pkg/analyzer/lib/src/task/driver.dart
@@ -280,7 +280,10 @@ class AnalysisDriver {
       if (task.caughtException == null) {
         List<TargetedResult> dependedOn = item.inputTargetedResults.toList();
         Map<ResultDescriptor, dynamic> outputs = task.outputs;
-        for (ResultDescriptor result in task.descriptor.results) {
+        List<ResultDescriptor> results = task.descriptor.results;
+        int resultLength = results.length;
+        for (int i = 0; i < resultLength; i++) {
+          ResultDescriptor result = results[i];
           // TODO(brianwilkerson) We could check here that a value was produced
           // and throw an exception if not (unless we want to allow null values).
           entry.setValue(result, outputs[result], dependedOn);