[Sheriff] Mark new regression test as flaky.

BUG=336820
LOG=n
R=bmeurer@chromium.org
TBR=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/139923007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18990 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/mjsunit/mjsunit.status

@@ -111,6 +111,9 @@
   'compiler/alloc-number-debug': [PASS, ['mode == release', SKIP]],
   'regress/regress-634': [PASS, ['mode == debug', SKIP]],
   'regress/regress-634-debug': [PASS, ['mode == release', SKIP]],
+
+  # BUG(336820). TODO(bmeurer): Investigate.
+  'regress/regress-336820': [PASS, FAIL],
 }],  # ALWAYS
 
 ##############################################################################