[Sheriff] Mark new regression test as flaky.

test/mjsunit/mjsunit.status

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 93 matching lines @@
   # Tests verifying CHECK and ASSERT.
   'verify-check-false': [FAIL, NO_VARIANTS],
   'verify-assert-false': [NO_VARIANTS, ['mode == release', PASS], ['mode == debug', FAIL]],
 
   ##############################################################################
   # Tests with different versions for release and debug.
   'compiler/alloc-number': [PASS, ['mode == debug', SKIP]],
   '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
 
 ##############################################################################
 ['gc_stress == True', {
   # Skip tests not suitable for GC stress.
   'allocation-site-info': [SKIP],
   'array-constructor-feedback': [SKIP],
   'array-feedback': [SKIP],
   'array-literal-feedback': [SKIP],
   'd8-performance-now': [SKIP],
@@ skipping 155 matching lines @@
   'never-optimize': [SKIP],
   'regress/regress-2185-2': [SKIP],
   'harmony/object-observe': [SKIP],
   'readonly': [SKIP],
   'array-feedback': [SKIP],
 
   # Deopt every n garbage collections collides with deopt every n times.
   'regress/regress-2653': [SKIP],
 }],  # 'deopt_fuzzer == True'
 ]