[[DefineOwnProperty]] should always return true/false (or throw an exception), never undefined.

Note that this is not an observable behavior, but following the principle of
least surprise, we should follow the spec. Additional (extremely tiny) bonus:
Some ICs see fewer values => better code.
Review URL: http://codereview.chromium.org/8352004

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9706 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/v8natives.js

@@ -704,7 +704,7 @@ function DefineObjectProperty(obj, p, desc, should_throw) {
     if (should_throw) {
       throw MakeTypeError("define_disallowed", [p]);
     } else {
-      return;
+      return false;
     }
   }
 
@@ -734,7 +734,7 @@ function DefineObjectProperty(obj, p, desc, should_throw) {
         if (should_throw) {
           throw MakeTypeError("redefine_disallowed", [p]);
         } else {
-          return;
+          return false;
         }
       }
       // Step 8
@@ -744,7 +744,7 @@ function DefineObjectProperty(obj, p, desc, should_throw) {
           if (should_throw) {
             throw MakeTypeError("redefine_disallowed", [p]);
           } else {
-            return;
+            return false;
           }
         }
         // Step 10a
@@ -753,7 +753,7 @@ function DefineObjectProperty(obj, p, desc, should_throw) {
             if (should_throw) {
               throw MakeTypeError("redefine_disallowed", [p]);
             } else {
-              return;
+              return false;
             }
           }
           if (!current.isWritable() && desc.hasValue() &&
@@ -761,7 +761,7 @@ function DefineObjectProperty(obj, p, desc, should_throw) {
             if (should_throw) {
               throw MakeTypeError("redefine_disallowed", [p]);
             } else {
-              return;
+              return false;
             }
           }
         }
@@ -771,14 +771,14 @@ function DefineObjectProperty(obj, p, desc, should_throw) {
             if (should_throw) {
               throw MakeTypeError("redefine_disallowed", [p]);
             } else {
-              return;
+              return false;
             }
           }
           if (desc.hasGetter() && !SameValue(desc.getGet(),current.getGet())) {
             if (should_throw) {
               throw MakeTypeError("redefine_disallowed", [p]);
             } else {
-              return;
+              return false;
             }
           }
         }
@@ -881,7 +881,7 @@ function DefineArrayProperty(obj, p, desc, should_throw) {
       if (should_throw) {
         throw MakeTypeError("define_disallowed", [p]);
       } else {
-        return;
+        return false;
       }
     }
     if (index >= length) {