Introduce CodeSourceMap object to hold pc -> token position mappings

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/growable_array.h"
 #include "vm/object.h"
 #include "vm/snapshot_ids.h"
@@ skipping 143 matching lines @@
   V(LiteralToken, "LiteralToken")                                              \
   V(TokenStream, "TokenStream")                                                \
   V(Script, "Script")                                                          \
   V(LibraryClass, "Library")                                                   \
   V(LibraryPrefix, "LibraryPrefix")                                            \
   V(Namespace, "Namespace")                                                    \
   V(Code, "Code")                                                              \
   V(Instructions, "Instructions")                                              \
   V(ObjectPool, "ObjectPool")                                                  \
   V(PcDescriptors, "PcDescriptors")                                            \
+  V(CodeSourceMap, "CodeSourceMap")                                            \
   V(Stackmap, "Stackmap")                                                      \
   V(LocalVarDescriptors, "LocalVarDescriptors")                                \
   V(ExceptionHandlers, "ExceptionHandlers")                                    \
   V(DeoptInfo, "DeoptInfo")                                                    \
   V(Context, "Context")                                                        \
   V(ContextScope, "ContextScope")                                              \
   V(ICData, "ICData")                                                          \
   V(MegamorphicCache, "MegamorphicCache")                                      \
   V(SubtypeTestCache, "SubtypeTestCache")                                      \
   V(Error, "Error")                                                            \
@@ skipping 482 matching lines @@
   friend class SnapshotReader;
   friend class SnapshotWriter;
   friend class ApiMessageReader;
 
   DISALLOW_COPY_AND_ASSIGN(Symbols);
 };
 
 }  // namespace dart
 
 #endif  // VM_SYMBOLS_H_