Change global const handling to silently ignore redeclarations

test/mjsunit/regress/regress-1213575.js

Index: test/mjsunit/regress/regress-1213575.js
diff --git a/test/mjsunit/regress/regress-1213575.js b/test/mjsunit/regress/regress-1213575.js
index 9d82064e4730aff403da71c6a4d34f4c0a915645..f3a11dbaab049bbc01dbdc9ba0f09d79598d03f7 100644
--- a/test/mjsunit/regress/regress-1213575.js
+++ b/test/mjsunit/regress/regress-1213575.js
@@ -25,17 +25,16 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-// Make sure that a const definition always
-// conflicts with a defined setter. This avoid
-// trying to pass 'the hole' to the setter.
+// Make sure that a const definition does not try
+// to pass 'the hole' to a defined setter.
 
-this.__defineSetter__('x', function(value) { assertTrue(false); });
+this.__defineSetter__('x', function(value) { assertTrue(value === 1); });
 
 var caught = false;
 try {
-  eval('const x');
+  eval('const x = 1');
 } catch(e) {
   assertTrue(e instanceof TypeError);
   caught = true;
 }
-assertTrue(caught);
+assertFalse(caught);