Fixes for exit problems.

pkg/analyzer/bin/analyzer.dart

Index: pkg/analyzer/bin/analyzer.dart
diff --git a/pkg/analyzer/bin/analyzer.dart b/pkg/analyzer/bin/analyzer.dart
index 76510c0b8cf772e95af781be8e545c64d1974851..19de8caa77e50b392c46c5b0930cff3d3c469b24 100644
--- a/pkg/analyzer/bin/analyzer.dart
+++ b/pkg/analyzer/bin/analyzer.dart
@@ -95,7 +95,7 @@ class BatchRunner {
    * Run the tool in 'batch' mode, receiving command lines through stdin and returning pass/fail
    * status through stdout. This feature is intended for use in unit testing.
    */
-  static ErrorSeverity runAsBatch(List<String> sharedArgs, BatchRunnerHandler handler) {
+  static void runAsBatch(List<String> sharedArgs, BatchRunnerHandler handler) {
     stdout.writeln('>>> BATCH START');
     Stopwatch stopwatch = new Stopwatch();
     stopwatch.start();
@@ -111,7 +111,7 @@ class BatchRunner {
       if (line.isEmpty) {
         var time = stopwatch.elapsedMilliseconds;
         stdout.writeln('>>> BATCH END (${totalTests - testsFailed}/$totalTests) ${time}ms');
-        exit(batchResult.ordinal);
+        exitCode = batchResult.ordinal;
       }
       // prepare aruments
       var args;