Build both a partial renderer and fizz renderer of the legacy API for…

… FB (#22933)

This lets us test how the new architecture performs without comparing it to
other infra changes related to streaming.

I renamed the streaming one to ReactDOMServerStreaming so the references
in www need to be updated.

I'll open an adhoc sync with just those files.

scripts/rollup/bundles.js

@@ -259,9 +259,14 @@ const bundles = [
 
  /******* React DOM Server *******/
  {
- bundleTypes: __EXPERIMENTAL__
- ? [UMD_DEV, UMD_PROD, NODE_DEV, NODE_PROD]
- : [UMD_DEV, UMD_PROD, NODE_DEV, NODE_PROD, FB_WWW_DEV, FB_WWW_PROD],
+ bundleTypes: [
+ UMD_DEV,
+ UMD_PROD,
+ NODE_DEV,
+ NODE_PROD,
+ FB_WWW_DEV,
+ FB_WWW_PROD,
+ ],
  moduleType: RENDERER,
  entry: 'react-dom/src/server/ReactDOMLegacyServerBrowser',
  name: 'react-dom-server-legacy.browser',
@@ -317,7 +322,7 @@ const bundles = [
  bundleTypes: __EXPERIMENTAL__ ? [FB_WWW_DEV, FB_WWW_PROD] : [],
  moduleType: RENDERER,
  entry: 'react-server-dom-relay/src/ReactDOMServerFB',
- global: 'ReactDOMServer',
+ global: 'ReactDOMServerStreaming',
  minifyWithProdErrorCodes: false,
  wrapWithModuleBoundaries: false,
  externals: ['react'],