Save exception and stack trace variables in async catch clauses and use them

runtime/vm/symbols.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_SYMBOLS_H_
 #define VM_SYMBOLS_H_
 
 #include "vm/object.h"
 #include "vm/snapshot_ids.h"
 
@@ skipping 61 matching lines @@
   V(Interpolate, "_interpolate")                                               \
   V(InterpolateSingle, "_interpolateSingle")                                   \
   V(Iterator, "iterator")                                                      \
   V(NoSuchMethod, "noSuchMethod")                                              \
   V(CurrentContextVar, ":current_context_var")                                 \
   V(SavedTryContextVar, ":saved_try_context_var")                              \
   V(ExceptionParameter, ":exception")                                          \
   V(StackTraceParameter, ":stack_trace")                                       \
   V(ExceptionVar, ":exception_var")                                            \
   V(StackTraceVar, ":stack_trace_var")                                         \
+  V(SavedExceptionVar, ":saved_exception_var")                                 \
+  V(SavedStackTraceVar, ":saved_stack_trace_var")                              \
   V(ListLiteralElement, "list literal element")                                \
   V(ForInIter, ":for-in-iter")                                                 \
   V(Library, "library")                                                        \
   V(LoadLibrary, "loadLibrary")                                                \
   V(_LibraryPrefix, "_LibraryPrefix")                                          \
   V(Async, "async")                                                            \
   V(Sync, "sync")                                                              \
   V(YieldKw, "yield")                                                          \
   V(AsyncCompleter, ":async_completer")                                        \
   V(AsyncOperation, ":async_op")                                               \
@@ skipping 489 matching lines @@
   friend class SnapshotReader;
   friend class SnapshotWriter;
   friend class ApiMessageReader;
 
   DISALLOW_COPY_AND_ASSIGN(Symbols);
 };
 
 }  // namespace dart
 
 #endif  // VM_SYMBOLS_H_