Fix store_mode bug involving polymorphism with external and JS arrays.

test/mjsunit/regress/external-and-normal-array-polymorphim.js

Index: test/mjsunit/regress/external-and-normal-array-polymorphim.js
diff --git a/test/mjsunit/copy-on-write-assert.js b/test/mjsunit/regress/external-and-normal-array-polymorphim.js
similarity index 81%
copy from test/mjsunit/copy-on-write-assert.js
copy to test/mjsunit/regress/external-and-normal-array-polymorphim.js
index 0e78c77befe4c4794446923c0bcf45df27c6fbac..59fada413c6f4c0e489b13d746a768d5cdac3d9e 100644
--- a/test/mjsunit/copy-on-write-assert.js
+++ b/test/mjsunit/regress/external-and-normal-array-polymorphim.js
@@ -25,18 +25,26 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-function createLargeCOWArray() {
-  var s = "[0";
-  // The constant below depends on the max object size in new space.
-  for (var i = 0; i < (128 << 10); i++) {
-    s += ",0";
+// Flags: --compiled_keyed_stores --compiled_transitions
+
+function store_generator(compare) {
+  return function(a,i,v) {
+    a[i] = v;
+    assertEquals(compare, a[i]);
+    assertEquals(compare, a[i]);
   }
-  s += "]";
-  return eval(s);
 }
 
-var large_cow_array = createLargeCOWArray();
+f = store_generator(5);
+a = [0,0,0];
+f(a,0,5);
+a = [0,0,0];
+f(a,1,5);
+a = [0,0,0];
+f(a,2,5);
 
-// Force copy. Because the array is large it will test the slow array
-// cloning in large object space.
-large_cow_array[17] = 42;
+f = store_generator(5.5);
+a = new Float32Array(5);
+f(a,0,5.5);
+f(a,1,5.5);
+f(a,2,5.5);