Update CSS Modules localIndetName (#4192)

* Update CSS Modules localIndetName

* Add missing file to package

* Correct regex

* plz plz plz

packages/react-dev-utils/getCSSModuleLocalIdent.js

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+'use strict';
+
+const loaderUtils = require('loader-utils');
+
+module.exports = function getLocalIdent(
+  context,
+  localIdentName,
+  localName,
+  options
+) {
+  // Use the filename or folder name, based on some uses the index.js / index.module.css project style
+  const fileNameOrFolder = context.resourcePath.endsWith('index.module.css')
+    ? '[folder]'
+    : '[name]';
+  // Create a hash based on a the file location and class name. Will be unique across a project, and close to globally unique.
+  const hash = loaderUtils.getHashDigest(
+    context.resourcePath + localName,
+    'md5',
+    'base64',
+    5
+  );
+  // Use loaderUtils to find the file or folder name
+  const className = loaderUtils.interpolateName(
+    context,
+    fileNameOrFolder + '_' + localName + '__' + hash,
+    options
+  );
+  // remove the .module that appears in every classname when based on the file.
+  return className.replace('.module_', '_');
+};