VM: Zero-cost try-finally with an empty finally-block.

runtime/vm/ast.h

 // Copyright (c) 2012, 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.
 
 #ifndef VM_AST_H_
 #define VM_AST_H_
 
 #include "platform/assert.h"
 #include "vm/allocation.h"
 #include "vm/growable_array.h"
@@ skipping 1857 matching lines @@
         rethrow_stacktrace_var_(*rethrow_stacktrace_var),
         catch_handler_index_(catch_handler_index),
         needs_stacktrace_(needs_stacktrace) {
     ASSERT(catch_block_ != NULL);
     ASSERT(handler_types.IsZoneHandle());
     ASSERT(context_var != NULL);
     ASSERT(exception_var != NULL);
     ASSERT(stacktrace_var != NULL);
   }
 
+  SequenceNode* sequence() const { return catch_block_; }
   const Array& handler_types() const { return handler_types_; }
   const LocalVariable& context_var() const { return context_var_; }
   const LocalVariable& exception_var() const { return exception_var_; }
   const LocalVariable& stacktrace_var() const { return stacktrace_var_; }
   const LocalVariable& rethrow_exception_var() const {
       return rethrow_exception_var_;
   }
   const LocalVariable& rethrow_stacktrace_var() const {
       return rethrow_stacktrace_var_;
   }
@@ skipping 131 matching lines @@
   const intptr_t try_index_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(InlinedFinallyNode);
 };
 
 }  // namespace dart
 
 #undef DECLARE_COMMON_NODE_FUNCTIONS
 
 #endif  // VM_AST_H_