Have --print-metrics use stderr to work around issue with analyzer_cli

runtime/vm/isolate.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/isolate.h"
 
 #include "include/dart_api.h"
 #include "include/dart_native_api.h"
 #include "platform/assert.h"
 #include "platform/text_buffer.h"
@@ skipping 1612 matching lines @@
     MegamorphicCacheTable::PrintSizes(this);
   }
   if (FLAG_trace_isolates) {
     heap()->PrintSizes();
     Symbols::DumpStats();
     OS::Print("[-] Stopping isolate:\n"
               "\tisolate:    %s\n", name());
   }
   if (FLAG_print_metrics) {
     LogBlock lb;
-    THR_Print("Printing metrics for %s\n", name());
+    fprintf(stderr, "Printing metrics for %s\n", name());
 #define ISOLATE_METRIC_PRINT(type, variable, name, unit)                       \
-  THR_Print("%s\n", metric_##variable##_.ToString());
+  fprintf(stderr, "%s\n", metric_##variable##_.ToString());
 
     ISOLATE_METRIC_LIST(ISOLATE_METRIC_PRINT);
 #undef ISOLATE_METRIC_PRINT
-    THR_Print("\n");
+    fprintf(stderr, "\n");
   }
 }
 
 
 void Isolate::StopBackgroundCompiler() {
   // Wait until all background compilation has finished.
   if (background_compiler_ != NULL) {
     BackgroundCompiler::Stop(this);
   }
 }
@@ skipping 1202 matching lines @@
 void IsolateSpawnState::DecrementSpawnCount() {
   ASSERT(spawn_count_monitor_ != NULL);
   ASSERT(spawn_count_ != NULL);
   MonitorLocker ml(spawn_count_monitor_);
   ASSERT(*spawn_count_ > 0);
   *spawn_count_ = *spawn_count_ - 1;
   ml.Notify();
 }
 
 }  // namespace dart