drop IE8- unshift fix

Author: zloirock

packages/core-js/modules/es.array.unshift.js

@@ -6,9 +6,6 @@ var setArrayLength = require('../internals/array-set-length');
 var deletePropertyOrThrow = require('../internals/delete-property-or-throw');
 var doesNotExceedSafeInteger = require('../internals/does-not-exceed-safe-integer');
 
-// IE8-
-var INCORRECT_RESULT = [].unshift(0) !== 1;
-
 // V8 ~ Chrome < 71 and Safari <= 15.4, FF < 23 throws InternalError
 var properErrorOnNonWritableLength = function () {
   try {
@@ -18,7 +15,7 @@ var properErrorOnNonWritableLength = function () {
   }
 };
 
-var FORCED = INCORRECT_RESULT || !properErrorOnNonWritableLength();
+var FORCED = !properErrorOnNonWritableLength();
 
 // `Array.prototype.unshift` method
 // https://tc39.es/ecma262/#sec-array.prototype.unshift

tests/compat/tests.js

@@ -859,7 +859,6 @@ GLOBAL.tests = {
     return Array.prototype[Symbol.unscopables].flatMap;
   },
   'es.array.unshift': function () {
-    if ([].unshift(0) !== 1) return false;
     try {
       Object.defineProperty([], 'length', { writable: false }).unshift();
     } catch (error) {