Change test262 test expectations regarding inaccurate Math functions.

test/test262/test262.status

Index: test/test262/test262.status
diff --git a/test/test262/test262.status b/test/test262/test262.status
index 4d8241879364866eba1005ea6b4c1fddef4623be..16a478ba119bd0c96824a3d85972f6937a4d57d6 100644
--- a/test/test262/test262.status
+++ b/test/test262/test262.status
@@ -48,12 +48,12 @@ S10.4.2.1_A1: FAIL
 # octal numbers in order to not break the web.
 S15.1.2.2_A5.1_T1: FAIL_OK
 
-# This tests precision of trignometric functions.  We're slightly off
-# from the implementation in libc (~ 1e-17) but it's not clear if we
-# or they are closer to the right answer, or if it even matters.
+# This tests precision of Math.tan and Math.sin.  The implementation for those
+# trigonometric functions are platform/compiler dependent.  Furthermore, the
+# expectation values by far deviates from the actual result given by an
+# arbitrary-precision calculator, making those tests partly bogus.
 S15.8.2.16_A7: PASS || FAIL_OK
 S15.8.2.18_A7: PASS || FAIL_OK
-S15.8.2.13_A23: PASS || FAIL_OK
 
 # We are more lenient in which string character escapes we allow than
 # the spec (7.8.4 p. 19) wants us to be.  This is for compatibility.