Update test failure from merge conflict.

A test written on 12 Sep was merged on 24 Sep. In between, the Props
definition it used changed so that the new test was an error.

This PR just clones the original Props type and gives it a new name.

types/react/test/index.ts

@@ -402,7 +402,13 @@ const ForwardingRefComponent = React.forwardRef((props: {}, ref: React.Ref<RefCo
     return React.createElement(RefComponent, { ref });
 });
 
-const ForwardingRefComponentPropTypes: React.WeakValidationMap<Props> = {};
+interface AttributeProps extends React.Attributes {
+    hello: string;
+    world?: string | null;
+    foo: number;
+}
+
+const ForwardingRefComponentPropTypes: React.WeakValidationMap<AttributeProps> = {};
 ForwardingRefComponent.propTypes = ForwardingRefComponentPropTypes;
 
 function RefCarryingComponent() {