Handle escapes in string literals.

frog/tests/leg/src/StringEscapesTest.dart

+// Copyright (c) 2011, 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("compiler_helper.dart");
+
+// Test that the compiler handles string literals containing line terminators.
+
+String compileExpression(String expression) {
+  var source = "foo() { return $expression; }";
+  return compile(source, "foo");
+}
+
+main() {
+  String generated = compileExpression("'''\n\r\u2028\u2029'''");
+  Expect.isTrue(generated.contains(@"\n\r\u2028\u2029"));
+
+  generated = compileExpression("@'''\n\r\u2028\u2029'''");
+  Expect.isTrue(generated.contains(@"\n\r\u2028\u2029"));
+
+  generated = compileExpression("'\u2028\u2029'");
+  Expect.isTrue(generated.contains(@"\u2028\u2029"));
+}