ES2015 web compat workaround: RegExp.prototype.flags => ""

test/test262/test262.status

Index: test/test262/test262.status
diff --git a/test/test262/test262.status b/test/test262/test262.status
index e8c4c5eeadf771df50ff5f935038284e4137bba9..314a0f8fd0952cb9f25ffa721da7d4c9fb33f10d 100644
--- a/test/test262/test262.status
+++ b/test/test262/test262.status
@@ -385,6 +385,12 @@
   # https://bugs.chromium.org/p/v8/issues/detail?id=4639
   'built-ins/ArrayBuffer/allocation-limit': [SKIP],
 
+  # https://code.google.com/p/chromium/issues/detail?id=581577
+  'built-ins/RegExp/prototype/source/15.10.7.1-1': [FAIL],
+  'built-ins/RegExp/prototype/global/15.10.7.2-1': [FAIL],
+  'built-ins/RegExp/prototype/ignoreCase/15.10.7.3-1': [FAIL],
+  'built-ins/RegExp/prototype/multiline/15.10.7.4-1': [FAIL],
+
   ######################## NEEDS INVESTIGATION ###########################
 
   # These test failures are specific to the intl402 suite and need investigation