Support Smi->Double->HeapObject transitions in constructed Arrays.

test/mjsunit/array-construct-transition.js

Index: test/mjsunit/array-construct-transition.js
diff --git a/test/mjsunit/array-construct-transition.js b/test/mjsunit/array-construct-transition.js
new file mode 100644
index 0000000000000000000000000000000000000000..5865e3320d0e98311b53a822972081dcfe251aa7
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+++ b/test/mjsunit/array-construct-transition.js
@@ -0,0 +1,39 @@
+// Copyright 2011 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: --allow-natives-syntax --smi-only-arrays
+
+support_smi_only_arrays = %HasFastSmiOnlyElements([1,2,3,4,5,6,7,8,9,10]);
+
+if (support_smi_only_arrays) {
+  var a = new Array(0, 1, 2);
+  assertTrue(%HasFastSmiOnlyElements(a));
+  var b = new Array(0.5, 1.2, 2.3);
+  assertTrue(%HasFastDoubleElements(b));
+  var c = new Array(0.5, 1.2, new Object());
+  assertTrue(%HasFastElements(c));
+}