Make --always-opt also optimize toplevel code.

src/hydrogen.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/hydrogen.h"
 
 #include <algorithm>
 
 #include "src/v8.h"
 
@@ skipping 11250 matching lines @@
       break;
     }
     case Variable::LOOKUP:
       return Bailout(kUnsupportedLookupSlotInDeclaration);
   }
 }
 
 
 void HOptimizedGraphBuilder::VisitModuleDeclaration(
     ModuleDeclaration* declaration) {
-  UNREACHABLE();
+  return Bailout(kModuleDeclaration);
 }
 
 
 void HOptimizedGraphBuilder::VisitImportDeclaration(
     ImportDeclaration* declaration) {
   UNREACHABLE();
 }
 
 
 void HOptimizedGraphBuilder::VisitExportDeclaration(
@@ skipping 1188 matching lines @@
   if (ShouldProduceTraceOutput()) {
     isolate()->GetHTracer()->TraceHydrogen(name(), graph_);
   }
 
 #ifdef DEBUG
   graph_->Verify(false);  // No full verify.
 #endif
 }
 
 } }  // namespace v8::internal