Move ReactDOMFloat to react-dom/src/ (#26514)

This is not really part of the bindings, it's more part of the package
entry points. /shared/ is not really right neither because it's more
like an isomorphic entry point and not some utility.

Author: sebmarkbage

Diff for: packages/react-dom-bindings/src/shared/ReactDOMFloat.js renamed to packages/react-dom/src/ReactDOMFloat.js

@@ -55,12 +55,7 @@ import {
 } from 'react-dom-bindings/src/events/ReactDOMControlledComponent';
 import Internals from '../ReactDOMSharedInternals';
 
-export {
-  prefetchDNS,
-  preconnect,
-  preload,
-  preinit,
-} from 'react-dom-bindings/src/shared/ReactDOMFloat';
+export {prefetchDNS, preconnect, preload, preinit} from '../ReactDOMFloat';
 
 if (__DEV__) {
   if (

Diff for: packages/react-dom/src/client/ReactDOM.js

@@ -7,12 +7,7 @@
  * @flow
  */
 
-export {
-  preinit,
-  preload,
-  preconnect,
-  prefetchDNS,
-} from 'react-dom-bindings/src/shared/ReactDOMFloat';
+export {preinit, preload, preconnect, prefetchDNS} from '../ReactDOMFloat';
 
 export function createPortal() {
   throw new Error(