[es6] Object.getPrototypeOf should work with values

test/mjsunit/harmony/set-prototype-of.js

Index: test/mjsunit/harmony/set-prototype-of.js
diff --git a/test/mjsunit/harmony/set-prototype-of.js b/test/mjsunit/harmony/set-prototype-of.js
index 810220d1a8f217a773c3c31da10bea9ca3ef4d8e..e06215a0edfcca65a84b4524f017c9805e856d22 100644
--- a/test/mjsunit/harmony/set-prototype-of.js
+++ b/test/mjsunit/harmony/set-prototype-of.js
@@ -64,15 +64,9 @@ var valuesWithoutNull = coercibleValues.concat(undefined);
 function TestSetPrototypeOfCoercibleValues() {
   for (var i = 0; i < coercibleValues.length; i++) {
     var value = coercibleValues[i];
-    assertThrows(function() {
-      Object.getPrototypeOf(value);
-    }, TypeError);
-
+    var proto = Object.getPrototypeOf(value);
     assertEquals(Object.setPrototypeOf(value, {}), value);
-
-    assertThrows(function() {
-      Object.getPrototypeOf(value);
-    }, TypeError);
+    assertSame(proto, Object.getPrototypeOf(value));
   }
 }
 TestSetPrototypeOfCoercibleValues();