Move files in react package (#11294)

* Move files in react package

* Move test-only TypeScript definitions into tests subfolder

Author: gaearon

package.json

@@ -123,7 +123,7 @@
       "./scripts/jest/environment.js"
     ],
     "setupTestFrameworkScriptFile": "./scripts/jest/test-framework-setup.js",
-    "testRegex": "/__tests__/.*(\\.js|coffee|ts)$",
+    "testRegex": "/__tests__/.*(\\.js|\\.coffee|[^d]\\.ts)$",
     "moduleFileExtensions": [
       "js",
       "json",

packages/react/src/classic/__tests__/ReactContextValidator-test.js renamed to packages/react/src/__tests__/ReactContextValidator-test.js

@@ -1,6 +1,6 @@
-/// <reference path="../PropTypes.d.ts" />
-/// <reference path="../React.d.ts" />
-/// <reference path="../ReactDOM.d.ts" />
+/// <reference path="./testDefinitions/PropTypes.d.ts" />
+/// <reference path="./testDefinitions/React.d.ts" />
+/// <reference path="./testDefinitions/ReactDOM.d.ts" />
 
 /*!
  * Copyright (c) 2015-present, Facebook, Inc.