[Interpreter] Avoid dereferencing handles on BytecodeGenerator for AST operations.

src/compiler-dispatcher/compiler-dispatcher-job.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/compiler-dispatcher/compiler-dispatcher-job.h"
 
 #include "src/assert-scope.h"
 #include "src/global-handles.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
@@ skipping 152 matching lines @@
 
   status_ = CompileJobStatus::kInitial;
 }
 
 void CompilerDispatcherJob::InternalizeParsingResult() {
   DCHECK(ThreadId::Current().Equals(isolate_->thread_id()));
   DCHECK(status() == CompileJobStatus::kParsed ||
          status() == CompileJobStatus::kFailed);
 
   HandleScope scope(isolate_);
+
+  // Create a canonical handle scope before internalizing parsed values if
+  // compiling bytecode. This is required for off-thread bytecode generation.
+  std::unique_ptr<CanonicalHandleScope> canonical;
+  if (FLAG_ignition) canonical.reset(new CanonicalHandleScope(isolate_));
+
   Handle<SharedFunctionInfo> shared(function_->shared(), isolate_);
   Handle<Script> script(Script::cast(shared->script()), isolate_);
 
   parse_info_->set_script(script);
   parse_info_->set_context(handle(function_->context(), isolate_));
 
   // Do the parsing tasks which need to be done on the main thread. This will
   // also handle parse errors.
   parser_->Internalize(isolate_, script, parse_info_->literal() == nullptr);
   parser_->HandleSourceURLComments(isolate_, script);
 
   parse_info_->set_character_stream(nullptr);
   parse_info_->set_unicode_cache(nullptr);
   parser_.reset();
   unicode_cache_.reset();
   character_stream_.reset();
 }
 
 }  // namespace internal
 }  // namespace v8