Fix fall out from hide isolate pointer change

runtime/vm/debugger_api_impl.cc

Index: runtime/vm/debugger_api_impl.cc
diff --git a/runtime/vm/debugger_api_impl.cc b/runtime/vm/debugger_api_impl.cc
index 194861aef9adbe2124061a1c2bc111e072c5f457..f4f893e14c1477b8af779f41b37d774554af731a 100644
--- a/runtime/vm/debugger_api_impl.cc
+++ b/runtime/vm/debugger_api_impl.cc
@@ -976,14 +976,16 @@ DART_EXPORT Dart_Handle Dart_SetLibraryDebuggable(intptr_t library_id,
 
 
 DART_EXPORT Dart_Isolate Dart_GetIsolate(Dart_IsolateId isolate_id) {
-  Isolate* isolate = PortMap::GetIsolate(isolate_id);
-  return Api::CastIsolate(isolate);
+  // Dart_Isolate is now the same as Dart_IsolateId.
+  // TODO(johnmccutchan): Kill Dart_IsolateId.
+  return reinterpret_cast<Dart_Isolate>(isolate_id);
 }
 
 
 DART_EXPORT Dart_IsolateId Dart_GetIsolateId(Dart_Isolate dart_isolate) {
-  Isolate* isolate = Api::CastIsolate(dart_isolate);
-  return isolate->debugger()->GetIsolateId();
+  // Dart_Isolate is now the same as Dart_IsolateId.
+  // TODO(johnmccutchan): Kill Dart_IsolateId.
+  return reinterpret_cast<Dart_IsolateId>(dart_isolate);
 }
 
 }  // namespace dart