Fixes issue 712 causing non-configurable accessors to be overwritable by usin...

src/runtime.js

Index: src/runtime.js
===================================================================
--- src/runtime.js	(revision 4684)
+++ src/runtime.js	(working copy)
@@ -562,15 +562,14 @@
   if (IS_NULL_OR_UNDEFINED(x)) return true;
   if (IS_NUMBER(x)) {
     if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true;
-    // x is +0 and y is -0 or vice versa
-    if (x === 0 && y === 0 && !%_IsSmi(x) && !%_IsSmi(y) &&
-        ((1 / x < 0 && 1 / y > 0) || (1 / x > 0 && 1 / y < 0))) {
+    // x is +0 and y is -0 or vice versa.
+    if (x === 0 && y === 0 && (1 / x) != (1 / y)) {
       return false;
     }
     return x == y;
   }
   if (IS_STRING(x)) return %StringEquals(x, y);
-  if (IS_BOOLEAN(x))return %NumberEquals(%ToNumber(x),%ToNumber(y));
+  if (IS_BOOLEAN(x)) return y == x;
 
   return %_ObjectEquals(x, y);
 }