Setup local var descriptors in kernel mode.

runtime/vm/kernel_to_il.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 <map>
 #include <set>
 #include <string>
 
 #include "vm/kernel_to_il.h"
 
@@ skipping 644 matching lines @@
       scope->VariableAt(i)->set_is_forced_stack();
     }
   }
 
   // Do not visit the positional and named parameters, because they've
   // already been added to the scope.
   if (node->body() != NULL) {
     node->body()->AcceptStatementVisitor(this);
   }
 
-  // Ensure that :await_jump_var and :await_ctx_var are captured.
+  // Ensure that :await_jump_var, :await_ctx_var and :async_op are captured.
   if (node->async_marker() == FunctionNode::kSyncYielding) {
     {
       LocalVariable* temp = NULL;
       LookupCapturedVariableByName(
           (depth_.function_ == 0) ? &result_->yield_jump_variable : &temp,
           Symbols::AwaitJumpVar());
     }
     {
       LocalVariable* temp = NULL;
       LookupCapturedVariableByName(
           (depth_.function_ == 0) ? &result_->yield_context_variable : &temp,
           Symbols::AwaitContextVar());
     }
+    {
+      LocalVariable* temp =
+          scope_->LookupVariable(Symbols::AsyncOperation(), true);
+      if (temp != NULL) {
+        scope_->CaptureVariable(temp);
+      }
+    }
   }
 }
 
 
 void ScopeBuilder::VisitYieldStatement(YieldStatement* node) {
   ASSERT(node->is_native());
   if (depth_.function_ == 0) {
     AddSwitchVariable();
     // Promote all currently visible local variables into the context.
     // TODO(27590) CaptureLocalVariables promotes to many variables into
@@ skipping 5148 matching lines @@
   instructions += LoadLocal(parsed_function_->current_context_var());
   instructions += StoreInstanceField(Closure::context_offset());
 
   return instructions;
 }
 
 
 }  // namespace kernel
 }  // namespace dart
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)