cps-ir: Implement boolean conversion in and use it to implement '&&', '||', and '?:'.

tests/compiler/dart2js/js_backend_cps_ir_operators.dart

+// Copyright (c) 2014, 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.
+
+// Tests of operators.
+
+library operators_tests;
+
+import 'js_backend_cps_ir_test.dart';
+
+const List<TestEntry> tests = const [
+  const TestEntry("main() { return true ? 42 : 'foo'; }"),
+  const TestEntry("""
+foo() => foo;
+main() {
+  print(foo() ? "hello world" : "bad bad");
+}""",
+"""function() {
+  P.print(P.identical(V.foo(), true) ? "hello world" : "bad bad");
+  return null;
+}"""),
+  const TestEntry("""
+get foo => foo;
+main() {
+  print(foo ? "hello world" : "bad bad");
+}""",
+"""function() {
+  P.print(P.identical(V.foo(), true) ? "hello world" : "bad bad");
+  return null;
+}"""),
+  const TestEntry("""
+get foo => foo;
+main() { print(foo && foo); }""",
+"""function() {
+  P.print(P.identical(V.foo(), true) && P.identical(V.foo(), true));
+  return null;
+}"""),
+  const TestEntry("""
+get foo => foo;
+main() { print(foo || foo); }""",
+"""function() {
+  P.print(P.identical(V.foo(), true) || P.identical(V.foo(), true));
+  return null;
+}"""),
+];