Temporarily disable test due to not being compatible with the serializer.

TBR=dslomov@chromium.org
BUG=v8:3689
LOG=N

Review URL: https://codereview.chromium.org/697893004

Cr-Commit-Position: refs/heads/master@{#25296}
git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@25296 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/mjsunit/mjsunit.status

@@ -51,6 +51,9 @@
   # Issue 3389: deopt_every_n_garbage_collections is unsafe
   'regress/regress-2653': [SKIP],
 
+  # Issue 3689: serializer does not handle internal symbols.
+  'regress/regress-2506': [PASS, FAIL],
+
   ##############################################################################
   # TurboFan compiler failures.