Delete setupEnvPolyfills.js which is no longer being used

jestSupport/setupEnvPolyfills.js

@@ -1,67 +0,0 @@
-/**
- * Copyright (c) 2015-present, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- *
- * This pipes all of our console logging functions to native logging so that
- * JavaScript errors in required modules show up in Xcode via NSLog.
- */
-
-'use strict';
-
-// WARNING: This is an optimized version that fails on hasOwnProperty checks
-// and non objects. It's not spec-compliant. It's a perf optimization.
-
-Object.assign = function(target, sources) {
-  if (__DEV__) {
-    if (target == null) {
-      throw new TypeError('Object.assign target cannot be null or undefined');
-    }
-    if (typeof target !== 'object' && typeof target !== 'function') {
-      throw new TypeError(
-        'In this environment the target of assign MUST be an object.' +
-        'This error is a performance optimization and not spec compliant.'
-      );
-    }
-  }
-
-  for (var nextIndex = 1; nextIndex < arguments.length; nextIndex++) {
-    var nextSource = arguments[nextIndex];
-    if (nextSource == null) {
-      continue;
-    }
-
-    if (__DEV__) {
-      if (typeof nextSource !== 'object' &&
-          typeof nextSource !== 'function') {
-        throw new TypeError(
-          'In this environment the target of assign MUST be an object.' +
-          'This error is a performance optimization and not spec compliant.'
-        );
-      }
-    }
-
-    // We don't currently support accessors nor proxies. Therefore this
-    // copy cannot throw. If we ever supported this then we must handle
-    // exceptions and side-effects.
-
-    for (var key in nextSource) {
-      if (__DEV__) {
-        var hasOwnProperty = Object.prototype.hasOwnProperty;
-        if (!hasOwnProperty.call(nextSource, key)) {
-          throw new TypeError(
-            'One of the sources to assign has an enumerable key on the ' +
-            'prototype chain. This is an edge case that we do not support. ' +
-            'This error is a performance optimization and not spec compliant.'
-          );
-        }
-      }
-      target[key] = nextSource[key];
-    }
-  }
-
-  return target;
-};