Disable key warning when element used as type

This gets serialized as a tuple in the Flight protocol so we think it needs
a key but it doesn't. It'll error later on the client.

Fix test asserting lazy because it's not actually executing the rendering
pass on the client since the transport is not live in Noop.

Technically this doesn't error if the Shared Component renders something
that can be a type since we actually resolve this component as if it is
just some value.

Author: sebmarkbage

packages/react-client/src/__tests__/ReactFlight-test.js

@@ -690,14 +690,19 @@ describe('ReactFlight', () => {
 
     const transport = ReactNoopFlightServer.render(<ServerComponent />);
 
-    await act(async () => {
-      const rootModel = await ReactNoopFlightClient.read(transport);
-      ReactNoop.render(rootModel);
-    });
-    expect(ReactNoop).toMatchRenderedOutput('Loading...');
-    spyOnDevAndProd(console, 'error').mockImplementation(() => {});
     await load();
-    expect(console.error).toHaveBeenCalledTimes(1);
+
+    await expect(async () => {
+      await act(async () => {
+        const rootModel = await ReactNoopFlightClient.read(transport);
+        ReactNoop.render(rootModel);
+      });
+    }).rejects.toThrow(
+      'Element type is invalid: expected a string (for built-in components) or a class/function ' +
+        '(for composite components) but got: <div />. ' +
+        'Did you accidentally export a JSX literal instead of a component?',
+    );
+    expect(ReactNoop).toMatchRenderedOutput(null);
   });
 
   it('can render a lazy element', async () => {

packages/react-server/src/ReactFlightServer.js

@@ -1591,6 +1591,14 @@ function renderElement(
           validated,
         );
       }
+      case REACT_ELEMENT_TYPE: {
+        // This is invalid but we'll let the client determine that it is.
+        if (__DEV__) {
+          // Disable the key warning that would happen otherwise because this
+          // element gets serialized inside an array. We'll error later anyway.
+          type._store.validated = 1;
+        }
+      }
     }
   }
   // For anything else, try it on the client instead.