[es6] Allow any valid repeat of empty string in String.prototype.repeat

test/test262/test262.status

 # Copyright 2011 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 350 matching lines @@
   'built-ins/Symbol/split/prop-desc': [FAIL],
   'built-ins/String/prototype/split/cstm-split-invocation': [FAIL],
   'built-ins/String/prototype/split/cstm-split-get-err': [FAIL],
 
   # https://code.google.com/p/v8/issues/detail?id=4346
   'built-ins/RegExp/prototype/flags/u': [FAIL],
 
   # https://code.google.com/p/v8/issues/detail?id=4361
   'intl402/Collator/10.1.1_a': [FAIL],
 
-  # https://code.google.com/p/v8/issues/detail?id=4362
-  'built-ins/String/prototype/repeat/empty-string-returns-empty': [PASS, FAIL],
-
   # https://code.google.com/p/v8/issues/detail?id=4447
   'built-ins/Function/prototype/Symbol.hasInstance/*': [SKIP],
   'built-ins/Symbol/hasInstance/prop-desc': [FAIL],
   'language/expressions/instanceof/symbol-hasinstance-get-err': [FAIL],
   'language/expressions/instanceof/symbol-hasinstance-invocation': [FAIL],
   'language/expressions/instanceof/symbol-hasinstance-to-boolean': [FAIL],
 
   # https://code.google.com/p/v8/issues/detail?id=3931
   'built-ins/Reflect/*': [FAIL],
 
@@ skipping 294 matching lines @@
   'language/statements/function/S13.2.2_A19_T8': [SKIP],
   'language/statements/while/S12.6.2_A4_T5': [SKIP],
 }],  # ignition == True
 
 ['ignition == True and (arch == arm or arch == arm64)', {
   'built-ins/encodeURI*': [SKIP],
   'intl402/9.2.2': [SKIP],
 }],  # ignition == True and (arch == arm or arch == arm64)
 
 ]