Remember deopt-id -> context-level mappings in var descriptors.

runtime/vm/scopes.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 RUNTIME_VM_SCOPES_H_
 #define RUNTIME_VM_SCOPES_H_
 
 #include "platform/assert.h"
 #include "platform/globals.h"
 #include "vm/allocation.h"
@@ skipping 302 matching lines @@
   // Two locals in different sibling scopes may share the same frame slot.
   // Return the index of the next available frame slot.
   int AllocateVariables(int first_parameter_index,
                         int num_parameters,
                         int first_frame_index,
                         LocalScope* context_owner,
                         bool* found_captured_variables);
 
   // Creates variable info for the scope and all its nested scopes.
   // Must be called after AllocateVariables() has been called.
-  RawLocalVarDescriptors* GetVarDescriptors(const Function& func);
+  RawLocalVarDescriptors* GetVarDescriptors(
+      const Function& func,
+      ZoneGrowableArray<intptr_t>* context_level_array);
 
   // Create a ContextScope object describing all captured variables referenced
   // from this scope and belonging to outer scopes.
   RawContextScope* PreserveOuterScope(int current_context_level) const;
 
   // Mark all local variables that are accessible from this scope up to
   // top_scope (included) as captured unless they are marked as forced to stack.
   void CaptureLocalVariables(LocalScope* top_scope);
 
   // Creates a LocalScope representing the outer scope of a local function to be
@@ skipping 40 matching lines @@
   // List of names referenced in this scope and its children that
   // are not resolved to local variables.
   GrowableArray<NameReference*> referenced_;
 
   DISALLOW_COPY_AND_ASSIGN(LocalScope);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_SCOPES_H_