Use a typed array for the irregexp stack.

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 321 matching lines @@
   V(OptimizedOut, "<optimized out>")                                           \
   V(NotInitialized, "<not initialized>")                                       \
   V(AllocationStubFor, "Allocation stub for ")                                 \
   V(TempParam, ":temp_param")                                                  \
   V(_UserTag, "_UserTag")                                                      \
   V(Default, "Default")                                                        \
   V(StubPrefix, "[Stub] ")                                                     \
   V(ClassID, "ClassID")                                                        \
   V(DartIsVM, "dart.isVM")                                                     \
   V(stack, ":stack")                                                           \
+  V(stack_pointer, ":stack_pointer")                                           \
   V(current_character, ":current_character")                                   \
   V(current_position, ":current_position")                                     \
   V(string_param_length, ":string_param_length")                               \
   V(capture_length, ":capture_length")                                         \
   V(word_character_map, ":word_character_map")                                 \
   V(match_start_index, ":match_start_index")                                   \
   V(capture_start_index, ":capture_start_index")                               \
   V(match_end_index, ":match_end_index")                                       \
   V(char_in_capture, ":char_in_capture")                                       \
   V(char_in_match, ":char_in_match")                                           \
@@ skipping 221 matching lines @@
   friend class SnapshotReader;
   friend class SnapshotWriter;
   friend class ApiMessageReader;
 
   DISALLOW_COPY_AND_ASSIGN(Symbols);
 };
 
 }  // namespace dart
 
 #endif  // VM_SYMBOLS_H_