Add initial hydrogenized NewStringAddStub.

test/mjsunit/new-string-add.js

-// Copyright 2009 the V8 project authors. All rights reserved.
+// Copyright 2013 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
 //       with the distribution.
 //     * Neither the name of Google Inc. nor the names of its
 //       contributors may be used to endorse or promote products derived
 //       from this software without specific prior written permission.
 //
 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+// Flags: --new-string-add
+
 assertEquals("ab", "a" + "b", "ll");
 
 assertEquals("12", "1" + "2", "dd");
 assertEquals("123", "1" + "2" + "3", "ddd");
 assertEquals("123", 1 + "2" + "3", "ndd");
 assertEquals("123", "1" + 2 + "3", "dnd");
 assertEquals("123", "1" + "2" + 3, "ddn");
 
 assertEquals("123", "1" + 2 + 3, "dnn");
 assertEquals("123", 1 + "2" + 3, "ndn");
@@ skipping 148 matching lines @@
   b[i] = non_ascii.substring(0, i);
 }
 
 // Add ascii and non-ascii strings generating strings with length from 0 to 20.
 for (var i = 0; i <= 20; i++) {
   for (var j = 0; j < i; j++) {
     assertEquals(a[i], a[j] + a[i - j])
     assertEquals(b[i], b[j] + b[i - j])
   }
 }