When deduplicating program metadata, try to use objects from the VM isolate.

runtime/vm/dart.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/dart.h"
 
 #include "vm/become.h"
 #include "vm/clustered_snapshot.h"
 #include "vm/code_observers.h"
 #include "vm/cpu.h"
@@ skipping 32 matching lines @@
 DECLARE_FLAG(bool, trace_time_all);
 DEFINE_FLAG(bool, keep_code, false, "Keep deoptimized code for profiling.");
 DEFINE_FLAG(bool, trace_shutdown, false, "Trace VM shutdown on stderr");
 
 Isolate* Dart::vm_isolate_ = NULL;
 int64_t Dart::start_time_micros_ = 0;
 ThreadPool* Dart::thread_pool_ = NULL;
 DebugInfo* Dart::pprof_symbol_generator_ = NULL;
 ReadOnlyHandles* Dart::predefined_handles_ = NULL;
 Snapshot::Kind Dart::vm_snapshot_kind_ = Snapshot::kInvalid;
+const uint8_t* Dart::vm_snapshot_instructions_ = NULL;
 Dart_ThreadExitCallback Dart::thread_exit_callback_ = NULL;
 Dart_FileOpenCallback Dart::file_open_callback_ = NULL;
 Dart_FileReadCallback Dart::file_read_callback_ = NULL;
 Dart_FileWriteCallback Dart::file_write_callback_ = NULL;
 Dart_FileCloseCallback Dart::file_close_callback_ = NULL;
 Dart_EntropySource Dart::entropy_source_callback_ = NULL;
 
 // Structure for managing read-only global handles allocation used for
 // creating global read-only handles that are pre created and initialized
 // for use across all isolates. Having these global pre created handles
@@ skipping 688 matching lines @@
   ASSERT(predefined_handles_ != NULL);
   return predefined_handles_->handles_.IsValidScopedHandle(address);
 }
 
 bool Dart::IsReadOnlyApiHandle(Dart_Handle handle) {
   ASSERT(predefined_handles_ != NULL);
   return predefined_handles_->api_handles_.IsValidHandle(handle);
 }
 
 }  // namespace dart