Adding ElementsAccessor::Concat

test/test262-es6/test262-es6.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 472 matching lines @@
   'language/expressions/prefix-decrement/S11.4.5_A5_*': [FAIL],
   'language/expressions/prefix-increment/S11.4.4_A5_*': [FAIL],
 
   # https://code.google.com/p/v8/issues/detail?id=4253
   'language/asi/S7.9_A5.7_T1': [PASS, FAIL_OK],
 
   # https://code.google.com/p/v8/issues/detail?id=3761
   'language/expressions/object/method-definition/generator-name-prop-symbol': [FAIL],
   'language/expressions/object/method-definition/name-name-prop-symbol': [FAIL],
 
-  # https://code.google.com/p/v8/issues/detail?id=4317
-  'built-ins/Array/prototype/concat/is-concat-spreadable-val-falsey': [FAIL],
-
   # https://code.google.com/p/v8/issues/detail?id=2952
   'built-ins/RegExp/prototype/exec/u-lastindex-adv': [FAIL],
   'built-ins/RegExp/prototype/exec/u-captured-value': [FAIL],
   'built-ins/RegExp/prototype/exec/u-lastindex-value': [FAIL],
   'built-ins/RegExp/prototype/test/u-captured-value': [FAIL],
   'built-ins/RegExp/prototype/test/u-lastindex-adv': [FAIL],
   'built-ins/RegExp/prototype/test/u-lastindex-value': [FAIL],
   'built-ins/RegExp/prototype/unicode/length': [FAIL],
   'built-ins/RegExp/prototype/unicode/name': [FAIL],
   'built-ins/RegExp/prototype/unicode/prop-desc': [FAIL],
@@ skipping 244 matching lines @@
 
   # BUG(3251225): Tests that timeout with --nocrankshaft.
   'built-ins/decodeURI/S15.1.3.1_A2.4_T1': [SKIP],
   'built-ins/decodeURI/S15.1.3.1_A2.5_T1': [SKIP],
   'built-ins/decodeURIComponent/S15.1.3.2_A2.4_T1': [SKIP],
   'built-ins/decodeURIComponent/S15.1.3.2_A2.5_T1': [SKIP],
   'built-ins/encodeURI/S15.1.3.3_A2.3_T1': [SKIP],
   'built-ins/encodeURIComponent/S15.1.3.4_A2.3_T1': [SKIP],
 }],  # 'arch == arm or arch == mipsel or arch == mips or arch == arm64'
 ]