Fix VM bug with try-catch inside of try-finally.

runtime/vm/code_descriptors.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_CODE_DESCRIPTORS_H_
 #define VM_CODE_DESCRIPTORS_H_
 
 #include "vm/ast.h"
 #include "vm/code_generator.h"
 #include "vm/globals.h"
@@ skipping 84 matching lines @@
   void AddHandler(intptr_t try_index,
                   intptr_t outer_try_index,
                   intptr_t pc_offset,
                   const Array& handler_types,
                   bool needs_stacktrace) {
     ASSERT(try_index >= 0);
     while (Length() <= try_index) {
       AddPlaceHolder();
     }
     list_[try_index].outer_try_index = outer_try_index;
+    ASSERT(list_[try_index].pc_offset == ExceptionHandlers::kInvalidPcOffset);
     list_[try_index].pc_offset = pc_offset;
     ASSERT(handler_types.IsZoneHandle());
     list_[try_index].handler_types = &handler_types;
     list_[try_index].needs_stacktrace |= needs_stacktrace;
   }
 
 
   // Called by rethrows, to mark their enclosing handlers.
   void SetNeedsStacktrace(intptr_t try_index) {
     // Rethrows can be generated outside a try by the compiler.
@@ skipping 20 matching lines @@
   RawExceptionHandlers* FinalizeExceptionHandlers(uword entry_point) const;
 
  private:
   GrowableArray<struct HandlerDesc> list_;
   DISALLOW_COPY_AND_ASSIGN(ExceptionHandlerList);
 };
 
 }  // namespace dart
 
 #endif  // VM_CODE_DESCRIPTORS_H_