S390: Skip slow test.

test/webkit/webkit.status

 # Copyright 2013 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 52 matching lines @@
   'reentrant-caching': [SKIP],
 }],  # 'dcheck_always_on == True and (arch == arm or arch == arm64)'
 ['arch == mips', {
   # Too slow for mips big-endian boards on bots (no FPU).
   'dfg-int-overflow-in-loop': [SKIP],
 }], # 'arch == mips'
 ['(arch == ppc or arch == ppc64) and simulator_run == True', {
   # Too slow.
   'dfg-int-overflow-in-loop': [SKIP],
 }], # 'arch == ppc or arch == ppc64'
+['arch == s390 or arch == s390x', {
+  # Too slow.
+  'dfg-int-overflow-in-loop': [SKIP],
+}],  # 'arch == s390 or arch == s390x'
 
 ##############################################################################
 ['asan == True', {
   # Skip tests not suitable for ASAN.
   'fast/js/excessive-comma-usage': [SKIP],
 
   # BUG(v8:4499).
   'run-json-stringify': [SKIP],
 }],  # 'asan == True'
 
@@ skipping 28 matching lines @@
 
 ##############################################################################
 ['gcov_coverage', {
   # Tests taking too long or getting too large call stacks.
   'fast/js/excessive-comma-usage': [SKIP],
   'run-json-stringify': [SKIP],
 }],  # 'gcov_coverage'
 
 ##############################################################################
 ]