Fix library snapshotting breakage with native entry symbol resolver

runtime/vm/native_entry.cc

 // Copyright (c) 2011, 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.
 
 #include "vm/native_entry.h"
 
 #include "include/dart_api.h"
 
 #include "vm/dart_api_impl.h"
 #include "vm/dart_api_state.h"
 #include "vm/object_store.h"
+#include "vm/reusable_handles.h"
 #include "vm/tags.h"
 
 
 namespace dart {
 
 DEFINE_FLAG(bool, trace_natives, false,
             "Trace invocation of natives (debug mode only)");
 
 
 static ExternalLabel native_call_label(
@@ skipping 16 matching lines @@
   Dart_NativeFunction native_function =
       resolver(Api::NewHandle(Isolate::Current(), function_name.raw()),
                number_of_arguments, auto_setup_scope);
   Dart_ExitScope();  // Exit the Dart API scope.
   return reinterpret_cast<NativeFunction>(native_function);
 }
 
 
 const uint8_t* NativeEntry::ResolveSymbolInLibrary(const Library& library,
                                                    uword pc) {
-  if (library.native_entry_symbol_resolver() == 0) {
+  Dart_NativeEntrySymbol symbol_resolver =
+      library.native_entry_symbol_resolver();
+  if (symbol_resolver == 0) {
     // Cannot reverse lookup native entries.
     return NULL;
   }
-  Dart_NativeEntrySymbol symbol_resolver =
-      library.native_entry_symbol_resolver();
   return symbol_resolver(reinterpret_cast<Dart_NativeFunction>(pc));
 }
 
 
 const uint8_t* NativeEntry::ResolveSymbol(uword pc) {
   Isolate* isolate = Isolate::Current();
-  const GrowableObjectArray& libs =
-      GrowableObjectArray::Handle(isolate->object_store()->libraries());
+  REUSABLE_GROWABLE_OBJECT_ARRAY_HANDLESCOPE(isolate);
+  GrowableObjectArray& libs = reused_growable_object_array_handle.Handle();
+  libs ^= isolate->object_store()->libraries();
   ASSERT(!libs.IsNull());
   intptr_t num_libs = libs.Length();
-  Library& lib = Library::Handle();
   for (intptr_t i = 0; i < num_libs; i++) {
+    REUSABLE_LIBRARY_HANDLESCOPE(isolate);
+    Library& lib = reused_library_handle.Handle();
     lib ^= libs.At(i);
     ASSERT(!lib.IsNull());
     const uint8_t* r = ResolveSymbolInLibrary(lib, pc);
     if (r != NULL) {
       return r;
     }
   }
   return NULL;
 }
 
@@ skipping 36 matching lines @@
     state->set_reusable_scope(scope);
   } else {
     ASSERT(state->reusable_scope() != scope);
     delete scope;
   }
   DEOPTIMIZE_ALOT;
   VERIFY_ON_TRANSITION;
 }
 
 }  // namespace dart