Corrected test broken by Node.js v0.10.27

Specifically, aae51ecf, which introduces deepEqual changes for comparing
argument objects---specifically, this change:

```c
  if ((aIsArgs && !bIsArgs) || (!aIsArgs && bIsArgs))
    return false;
```

Since I was comparing an array with an arguments object, deepEqual failed.
While such an implementation may confuse users---since argument objects are
generally treated like arrays---the distinction is important and I do agree
with the change.

test/MemberBuilder/MethodTest.js

@@ -78,7 +78,9 @@ require( 'common' ).testCase(
         var stubProxyFactory = this.require( 'MethodWrapperFactory' )(
              function()
              {
-                _self.proxyFactoryCall = arguments;
+                _self.proxyFactoryCall =
+                    Array.prototype.slice.call( arguments );
+
                 return _self.proxyReturnValue;
              }
         );