Do not allow native syntax on all libraries.

dart/frog/leg/compiler.dart

 // 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.
 
 class WorkItem {
   final Element element;
   TreeElements resolutionTree;
   Function run;
   Map<int, BailoutInfo> bailouts = null;
   bool allowSpeculativeOptimization = true;
@@ skipping 56 matching lines @@
   DietParserTask dietParser;
   ParserTask parser;
   TreeValidatorTask validator;
   ResolverTask resolver;
   TypeCheckerTask checker;
   SsaBuilderTask builder;
   SsaOptimizerTask optimizer;
   SsaCodeGeneratorTask generator;
   CodeEmitterTask emitter;
   CompileTimeConstantHandler compileTimeConstantHandler;
+  native.NativeHandler nativeHandler;
 
   static final SourceString MAIN = const SourceString('main');
   static final SourceString NO_SUCH_METHOD = const SourceString('noSuchMethod');
 
   Compiler() : this.withCurrentDirectory(io.getCurrentDirectory());
 
   Compiler.withCurrentDirectory(String this.currentDirectory)
       : types = new Types(),
         universe = new Universe(),
         worklist = new Queue<WorkItem>() {
     namer = new Namer(this);
     compileTimeConstantHandler = new CompileTimeConstantHandler(this);
     scanner = new ScannerTask(this);
     dietParser = new DietParserTask(this);
     parser = new ParserTask(this);
     validator = new TreeValidatorTask(this);
     resolver = new ResolverTask(this);
     checker = new TypeCheckerTask(this);
     builder = new SsaBuilderTask(this);
     optimizer = new SsaOptimizerTask(this);
     generator = new SsaCodeGeneratorTask(this);
     emitter = new CodeEmitterTask(this);
+    nativeHandler = new native.NativeHandler(this);
     tasks = [scanner, dietParser, parser, resolver, checker,
              builder, optimizer, generator,
-             emitter, compileTimeConstantHandler];
+             emitter, compileTimeConstantHandler, nativeHandler];
   }
 
   void ensure(bool condition) {
     if (!condition) cancel('failed assertion in leg');
   }
 
   void unimplemented(String methodName,
                      [Node node, Token token, HInstruction instruction,
                       Element element]) {
     cancel("$methodName not implemented", node, token, instruction, element);
@@ skipping 132 matching lines @@
             }
           }
         }
       }
     }
   }
 
   void runCompiler(Script script) {
     scanBuiltinLibraries();
     mainApp = new LibraryElement(script);
-    native.checkNativeSupport(this, mainApp, null);
+    nativeHandler.checkNativeSupport(mainApp, null);
 
     Element element;
     withCurrentElement(mainApp, () {
         scanner.scan(currentElement);
         element = mainApp.find(MAIN);
         if (element === null) cancel('Could not find $MAIN');
       });
     worklist.add(new WorkItem.toCompile(element));
     do {
       while (!worklist.isEmpty()) {
@@ skipping 134 matching lines @@
 
 class CompilerCancelledException implements Exception {
   final String reason;
   CompilerCancelledException(this.reason);
 
   String toString() {
     String banner = 'compiler cancelled';
     return (reason !== null) ? '$banner: $reason' : '$banner';
   }
 }