Ensure Array.prototype.indexOf returns +0 rather than -0

test/test262/test262.status

Index: test/test262/test262.status
diff --git a/test/test262/test262.status b/test/test262/test262.status
index a926bcc92dfe13e5a507d8b7db4a258f957e34f7..9b0003e989b2d07e59475fc9018d7ce547e7d3ab 100644
--- a/test/test262/test262.status
+++ b/test/test262/test262.status
@@ -331,11 +331,6 @@
   'intl402/Collator/prototype/compare/10.3.2_CS_d_NN': [PASS, FAIL_OK],
   'intl402/Date/prototype/13.3.0_7': [PASS, FAIL_OK],
 
-  # Some tests are too strict, checking SameValue rather than ===
-  # https://github.com/tc39/test262/issues/435
-  'built-ins/Array/prototype/indexOf/15.4.4.14-5-9': [FAIL],
-  'built-ins/Array/prototype/lastIndexOf/15.4.4.15-5-9': [FAIL],
-
   # https://github.com/tc39/test262/issues/489
   # Test will pass in 0 or -GMT, but fail in +GMT
   'language/statements/class/subclass/builtin-objects/Date/regular-subclassing': [PASS, FAIL_OK],