Don't mark closurized natives as natives.

runtime/vm/precompiler.cc

 // Copyright (c) 2015, 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/precompiler.h"
 
 #include "vm/aot_optimizer.h"
 #include "vm/assembler.h"
 #include "vm/ast_printer.h"
 #include "vm/branch_optimizer.h"
@@ skipping 1914 matching lines @@
       }
 
       code_ = function.CurrentCode();
       pool_ = code_.object_pool();
       for (intptr_t i = 0; i < pool_.Length(); i++) {
         if (pool_.InfoAt(i) != ObjectPool::kTaggedObject) continue;
         entry_ = pool_.ObjectAt(i);
         if (entry_.IsICData()) {
           ic_ ^= entry_.raw();
 
-          // Only single check ICs are SwitchableCalls that use the ICLookup
-          // stubs. Some operators like + have ICData that check the types of
-          // arguments in addition to the receiver and use special stubs
-          // with fast paths for Smi operations.
-          if (ic_.NumArgsTested() != 1) continue;
+          // SwitchableCalls use single-check ICs. No other kind of IC call is
+          // generated in precompilation mode.
+          ASSERT(ic_.NumArgsTested() == 1);
 
           for (intptr_t j = 0; j < ic_.NumberOfChecks(); j++) {
             entry_ = ic_.GetTargetOrCodeAt(j);
             if (entry_.IsFunction()) {
               target_ ^= entry_.raw();
               ASSERT(target_.HasCode());
               target_code_ = target_.CurrentCode();
               entry_point_ = Smi::FromAlignedAddress(target_code_.EntryPoint());
               ic_.SetCodeAt(j, target_code_);
               ic_.SetEntryPointAt(j, entry_point_);
@@ skipping 1000 matching lines @@
       CompilationPipeline::New(thread->zone(), function);
 
   ASSERT(FLAG_precompiled_mode);
   const bool optimized = function.IsOptimizable();  // False for natives.
   return PrecompileFunctionHelper(pipeline, function, optimized);
 }
 
 #endif  // DART_PRECOMPILER
 
 }  // namespace dart