Use predicates to check simple function types.

tests/compiler/dart2js/simple_function_subtype_test.dart

Index: tests/compiler/dart2js/simple_function_subtype_test.dart
diff --git a/tests/compiler/dart2js/simple_function_subtype_test.dart b/tests/compiler/dart2js/simple_function_subtype_test.dart
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+// Copyright (c) 2013, 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.
+
+// Test that simple function subtype checks use predicates.
+
+library simple_function_subtype_test;
+import "package:expect/expect.dart";
+import 'compiler_helper.dart';
+
+const String TEST = r"""
+typedef Args0();
+typedef Args1(a);
+typedef Args2(a, b);
+typedef Args3(a, b, c);
+typedef Args4(a, b, c, d);
+typedef Args5(a, b, c, d, e);
+typedef Args6(a, b, c, d, e, f);
+typedef Args7(a, b, c, d, e, f, g);
+typedef Args8(a, b, c, d, e, f, g, h);
+typedef Args9(a, b, c, d, e, f, g, h, i);
+typedef Args10(a, b, c, d, e, f, g, h, i, j);
+typedef Args11(a, b, c, d, e, f, g, h, i, j, k);
+typedef Args12(a, b, c, d, e, f, g, h, i, j, k, l);
+typedef Args13(a, b, c, d, e, f, g, h, i, j, k, l, m);
+typedef Args14(a, b, c, d, e, f, g, h, i, j, k, l, m, n);
+typedef Args15(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o);
+
+args5_10(a, b, c, d, e, [f, g, h, i, j]) {}
+
+foo() {
+  print(args5_10 is Args0);
+  print(args5_10 is Args1);
+  print(args5_10 is Args2);
+  print(args5_10 is Args3);
+  print(args5_10 is Args4);
+  print(args5_10 is Args5);
+  print(args5_10 is Args6);
+  print(args5_10 is Args7);
+  print(args5_10 is Args8);
+  print(args5_10 is Args9);
+  print(args5_10 is Args10);
+  print(args5_10 is Args11);
+  print(args5_10 is Args12);
+  print(args5_10 is Args13);
+  print(args5_10 is Args14);
+  print(args5_10 is Args15);
+}
+""";
+
+main() {
+  String generated = compile(TEST, entry: 'foo');
+  for (int i = 0 ; i <= 15  ; i++) {
+    String predicateCheck = '.\$is_args$i';
+    Expect.isTrue(generated.contains(predicateCheck),
+      'Expected predicate check $predicateCheck');
+  }
+  Expect.isFalse(generated.contains('checkFunctionSubtype'),
+    'Unexpected use of checkFunctionSubtype');
+}