Fixed read-only attribute of Function.length in strict mode.

test/mjsunit/regress/regress-function-length-strict.js

Index: test/mjsunit/regress/regress-function-length-strict.js
diff --git a/test/mjsunit/regress/regress-2489.js b/test/mjsunit/regress/regress-function-length-strict.js
similarity index 82%
copy from test/mjsunit/regress/regress-2489.js
copy to test/mjsunit/regress/regress-function-length-strict.js
index 882c4f794a88e24d1d64e86a466b27c39f51e625..700f34a67ad301e80878fbe7f27fcd5b68794655 100644
--- a/test/mjsunit/regress/regress-2489.js
+++ b/test/mjsunit/regress/regress-function-length-strict.js
@@ -25,26 +25,17 @@
 // (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
+// Test that the length property of a function is read-only in strict mode.
 
 "use strict";
 
-function f(a, b) {
-  return g("c", "d");
+function foo(a, b, c) {
+  return b;
 }
 
-function g(a, b) {
-  g.constructor.apply(this, arguments);
-}
-
-g.constructor = function(a, b) {
-  assertEquals("c", a);
-  assertEquals("d", b);
-}
-
-f("a", "b");
-f("a", "b");
-%OptimizeFunctionOnNextCall(f);
-f("a", "b");
-g.x = "deopt";
-f("a", "b");
+var desc = Object.getOwnPropertyDescriptor(foo, 'length');
+assertEquals(3, desc.value);
+assertFalse(desc.writable);
+assertFalse(desc.enumerable);
+assertFalse(desc.configurable);
+assertThrows(function() { foo.length = 2; }, TypeError);