Compute NativeBehavior for foreign functions.

tests/compiler/dart2js/kernel/impact_test.dart

 // Copyright (c) 2016, 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.
 
 library dart2js.kernel.impact_test;
 
 import 'dart:async';
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/commandline_options.dart';
 import 'package:compiler/src/common.dart';
@@ skipping 584 matching lines @@
     Compiler compiler = compilerFor(
         entryPoint: entryPoint,
         memorySourceFiles: SOURCE,
         options: [
           Flags.analyzeAll,
           Flags.useKernel,
           Flags.enableAssertMessage
         ]);
     compiler.resolution.retainCachesForTesting = true;
     await compiler.run(entryPoint);
-    checkLibrary(compiler, compiler.mainApp);
+    compiler.libraryLoader.libraries.forEach((LibraryElement library) {
+      checkLibrary(compiler, library);
+    });
   });
 }
 
 void checkLibrary(Compiler compiler, LibraryElement library) {
   library.forEachLocalMember((AstElement element) {
     if (element.isClass) {
       ClassElement cls = element;
       cls.forEachLocalMember((AstElement member) {
         checkElement(compiler, member);
       });
     } else if (element.isTypedef) {
       // Skip typedefs.
     } else {
       checkElement(compiler, element);
     }
   });
 }
 
 void checkElement(Compiler compiler, AstElement element) {
+  if (compiler.backend.isNative(element)) {
+    // Skip native functions for now; kernel does not provide their
+    // signature which we need to derive their native behavior.
+    return;
+  }
+  if (element.isConstructor) {
+    ConstructorElement constructor = element;
+    if (constructor.isRedirectingFactory) {
+      // Skip redirecting constructors for now; they might not be supported.
+      return;
+    }
+  }
   ResolutionImpact astImpact = compiler.resolution.getResolutionImpact(element);
   astImpact = laxImpact(compiler, element, astImpact);
   ResolutionImpact kernelImpact = build(compiler, element.resolvedAst);
   Expect.isNotNull(kernelImpact, 'No impact computed for $element');
   testResolutionImpactEquivalence(
       astImpact, kernelImpact, const CheckStrategy());
 }
 
 /// Lax the precision of [impact] to meet expectancy of the corresponding impact
 /// generated from kernel.
@@ skipping 79 matching lines @@
   @override
   DartType visitFunctionType(FunctionType type, _) {
     return new FunctionType.synthesized(
         visit(type.returnType),
         visitList(type.parameterTypes),
         visitList(type.optionalParameterTypes),
         type.namedParameters,
         visitList(type.namedParameterTypes));
   }
 }