VM: Fix product precompiler, it must have FLAG_use_osr set to false.

runtime/vm/clustered_snapshot.cc

 // Copyright (c) 2016, 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/clustered_snapshot.h"
 
 #include "platform/assert.h"
 #include "vm/bootstrap.h"
 #include "vm/class_finalizer.h"
 #include "vm/dart.h"
@@ skipping 5015 matching lines @@
 
   const char* expected_features = Dart::FeaturesString(isolate, kind_);
   ASSERT(expected_features != NULL);
   const intptr_t expected_len = strlen(expected_features);
 
   const char* features = reinterpret_cast<const char*>(CurrentBufferAddress());
   ASSERT(features != NULL);
   intptr_t buffer_len = OS::StrNLen(features, PendingBytes());
   if ((buffer_len != expected_len) ||
       strncmp(features, expected_features, expected_len)) {
-    const intptr_t kMessageBufferSize = 256;
+    const intptr_t kMessageBufferSize = 1024;
     char message_buffer[kMessageBufferSize];
     char* actual_features =
         OS::StrNDup(features, buffer_len < 128 ? buffer_len : 128);
     OS::SNPrint(message_buffer, kMessageBufferSize,
                 "Snapshot not compatible with the current VM configuration: "
                 "the snapshot requires '%s' but the VM has '%s'",
                 actual_features, expected_features);
     free(const_cast<char*>(expected_features));
     free(actual_features);
     // This can also fail while bringing up the VM isolate, so make sure to
@@ skipping 467 matching lines @@
     thread_->isolate()->SetupImagePage(data_buffer_,
                                        /* is_executable */ false);
   }
 
   deserializer.ReadIsolateSnapshot(thread_->isolate()->object_store());
 
   return ApiError::null();
 }
 
 }  // namespace dart