Parallelize test/mjsunit/es6/tail-call-megatest.js in order to avoid timeouts on slow architectures.

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
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@@ skipping 381 matching lines @@
   'regress/regress-3976': [SKIP],
 
   # BUG(v8:4359)
   'strong/load-proxy': [SKIP],
 
   # Slow tests.
   'array-constructor': [PASS, SLOW],
   'json': [PASS, SLOW],
   'regress/regress-446389': [PASS, SLOW],
   'regress/regress-inline-getter-near-stack-limit': [PASS, SLOW],
+  'es6/tail-call-megatest-all': [PASS, SLOW],
 
   # BUG(v8:3097)
   'debug-references': [SKIP],
 
   # BUG(v8:4754).
   'debug-referenced-by': [PASS, NO_VARIANTS],
 
   # BUG(v8:4779): Crashes flakily with stress mode on arm64.
   'array-splice': [PASS, SLOW, ['arch == arm64', FAST_VARIANTS]],
 }],  # 'gc_stress == True'
@@ skipping 491 matching lines @@
   # Tests taking too long.
   'array-functions-prototype-misc': [SKIP],
   'strong/implicit-conversions': [SKIP],
   'strong/load-element-mutate-backing-store': [SKIP],
 
   # Stack overflow.
   'big-array-literal': [SKIP],
 }],  # 'gcov_coverage'
 
 ]