Migrate language_2/abstract to NNBD.

Change-Id: I265933f36f68df6f8e542a3f85ce0b04e1dfd549
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/134205
Auto-Submit: Bob Nystrom <rnystrom@google.com>
Reviewed-by: Erik Ernst <eernst@google.com>
Commit-Queue: Bob Nystrom <rnystrom@google.com>

tests/language/abstract/exact_selector_runtime_test.dart

@@ -0,0 +1,40 @@
+// TODO(multitest): This was automatically migrated from a multitest and may
+// contain strange or dead code.
+
+// 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.
+
+// Regression test for dart2js that used to duplicate some `Object`
+// methods to handle `noSuchMethod`.
+
+import "package:expect/expect.dart";
+import "../compiler_annotations.dart";
+
+class Foo {
+  noSuchMethod(im) => 42;
+}
+
+@DontInline()
+returnFoo() {
+  (() => 42)();
+  return new Foo();
+}
+
+class Bar {
+  operator ==(other) => false;
+}
+
+var a = [false, true, new Object(), new Bar()];
+
+main() {
+  if (a[0] as bool) {
+    // This `==` call will make the compiler create a selector with an
+    // exact `TypeMask` of `Foo`. Since `Foo` is abstract, such a call
+    // cannot happen, but we still used to generate a `==` method on
+    // the `Object` class to handle `noSuchMethod`.
+    print(returnFoo() == 42);
+  } else {
+    Expect.isFalse(a[2] == 42);
+  }
+}

tests/language/abstract/factory_constructor_runtime_test.dart

@@ -0,0 +1,34 @@
+// TODO(multitest): This was automatically migrated from a multitest and may
+// contain strange or dead code.
+
+// 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.
+// Dart test program for constructors and initializers.
+
+// Exercises issue 2282, factory constructors in abstract classes should
+// not emit a static type warning
+
+class B extends A1 {
+  B() {}
+  method() {}
+}
+
+abstract class A1 {
+  A1() {}
+  method(); // Abstract.
+  factory A1.make() {
+    return new B();
+  }
+}
+
+class A2 {
+  // Intentionally abstract method.
+
+  A2.make() {}
+}
+
+main() {
+  new A1.make();
+
+}

tests/language/abstract/syntax_runtime_test.dart

@@ -0,0 +1,23 @@
+// TODO(multitest): This was automatically migrated from a multitest and may
+// contain strange or dead code.
+
+// 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.
+
+import "package:expect/expect.dart";
+
+main() {
+  var b = new B();
+  Expect.equals(42, b.foo());
+}
+
+class A {
+
+
+}
+
+class B extends A {
+  foo() => 42;
+  bar() => 87;
+}