[test] Remove tests from mjsunit.status that no longer exist.

R=mstarzinger@chromium.org
BUG=v8:4768
LOG=n

Review URL: https://codereview.chromium.org/1737273003

Cr-Commit-Position: refs/heads/master@{#34323}

test/mjsunit/mjsunit.status

@@ -845,11 +845,6 @@
   'es6/regress/regress-3280': [FAIL],
   'harmony/destructuring-assignment': [FAIL],
   'harmony/function-sent': [FAIL],
-  'harmony/reflect-enumerate-delete': [FAIL],
-  'harmony/reflect-enumerate-special-cases': [FAIL],
-  'harmony/proxies-enumerate': [FAIL],
-  'harmony/reflect-enumerate-opt': [FAIL],
-  'harmony/reflect-enumerate': [FAIL],
   'harmony/destructuring': [FAIL],
   'harmony/regress/regress-4482': [FAIL],
   'harmony/generators': [FAIL],