Revert of [test262-es6] Temporary disable some tests (patchset #1 id:1 of...

Revert of [test262-es6] Temporary disable some tests (patchset #1 id:1 of https://codereview.chromium.org/1176573002/)

Reason for revert:
[Sheriff] Prepares revert of https://codereview.chromium.org/1136553008

Original issue's description:
> [test262-es6] Temporary disable some tests
>
> These tests have issues with our harness.
>
> Upstream fix: https://github.com/tc39/test262/pull/309
>
> BUG=N
> LOG=N
> TBR=machenbach@chromium.org
>
> Committed: https://crrev.com/eed7363a0da0f21c3eee6c052507299d9b707462
> Cr-Commit-Position: refs/heads/master@{#28881}

TBR=arv@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=N

Review URL: https://codereview.chromium.org/1169903006

Cr-Commit-Position: refs/heads/master@{#28889}

test/test262-es6/test262-es6.status

@@ -389,34 +389,6 @@
   'language/statements/const/syntax/without-initializer-label-statement': [PASS, ['sloppy', FAIL]],
   'language/statements/const/syntax/without-initializer-while-expression-statement': [PASS, ['sloppy', FAIL]],
 
-
-  ###########################  HARNESS ISSUES ############################
-  'built-ins/Math/acosh/acosh-length': [PASS, FAIL],
-  'built-ins/Math/acosh/acosh-specialVals': [PASS, FAIL],
-  'built-ins/Math/asinh/asinh-length': [PASS, FAIL],
-  'built-ins/Math/asinh/asinh-specialVals': [PASS, FAIL],
-  'built-ins/Math/atanh/atanh-length': [PASS, FAIL],
-  'built-ins/Math/atanh/atanh-specialVals': [PASS, FAIL],
-  'built-ins/Math/cbrt/cbrt-length': [PASS, FAIL],
-  'built-ins/Math/cbrt/cbrt-specialValues': [PASS, FAIL],
-  'built-ins/Math/cosh/cosh-length': [PASS, FAIL],
-  'built-ins/Math/cosh/cosh-specialVals': [PASS, FAIL],
-  'built-ins/Math/expm1/expm1-length': [PASS, FAIL],
-  'built-ins/Math/expm1/expm1-specialVals': [PASS, FAIL],
-  'built-ins/Math/imul/imul-length': [PASS, FAIL],
-  'built-ins/Math/log10/Log10-length': [PASS, FAIL],
-  'built-ins/Math/log10/Log10-specialVals': [PASS, FAIL],
-  'built-ins/Math/log1p/Log1p-length': [PASS, FAIL],
-  'built-ins/Math/log2/log2-length': [PASS, FAIL],
-  'built-ins/Math/sign/sign-length': [PASS, FAIL],
-  'built-ins/Math/sign/sign-specialVals': [PASS, FAIL],
-  'built-ins/Math/sinh/sinh-length': [PASS, FAIL],
-  'built-ins/Math/sinh/sinh-specialVals': [PASS, FAIL],
-  'built-ins/Math/tanh/tanh-length': [PASS, FAIL],
-  'built-ins/Math/tanh/tanh-specialVals': [PASS, FAIL],
-  'built-ins/Math/trunc/trunc-length': [PASS, FAIL],
-  'built-ins/Math/trunc/trunc-specialVals': [PASS, FAIL],
-
   ##################### DELIBERATE INCOMPATIBILITIES #####################
 
   'built-ins/Math/exp/S15.8.2.8_A6': [PASS, FAIL_OK],  # Math.exp (less precise with --fast-math)