Teach the test runner whether it's running on a trybot or not

tools/run-tests.py

 #!/usr/bin/env python
 #
 # 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
@@ skipping 123 matching lines @@
                     default="ia32,x64,arm")
   result.add_option("--arch-and-mode",
                     help="Architecture and mode in the format 'arch.mode'",
                     default=None)
   result.add_option("--asan",
                     help="Regard test expectations for ASAN",
                     default=False, action="store_true")
   result.add_option("--buildbot",
                     help="Adapt to path structure used on buildbots",
                     default=False, action="store_true")
+  result.add_option("--dcheck-always-on",
+                    help="Indicates that V8 was compiled with DCHECKs enabled",
+                    default=False, action="store_true")
   result.add_option("--cat", help="Print the source of the tests",
                     default=False, action="store_true")
   result.add_option("--flaky-tests",
                     help="Regard tests marked as flaky (run|skip|dontcare)",
                     default="dontcare")
   result.add_option("--slow-tests",
                     help="Regard slow tests (run|skip|dontcare)",
                     default="dontcare")
   result.add_option("--pass-fail-tests",
                     help="Regard pass|fail tests (run|skip|dontcare)",
@@ skipping 347 matching lines @@
     "gc_stress": options.gc_stress,
     "isolates": options.isolates,
     "mode": mode,
     "no_i18n": options.no_i18n,
     "no_snap": options.no_snap,
     "simulator_run": simulator_run,
     "simulator": utils.UseSimulator(arch),
     "system": utils.GuessOS(),
     "tsan": options.tsan,
     "msan": options.msan,
+    "dcheck_always_on": options.dcheck_always_on,
   }
   all_tests = []
   num_tests = 0
   test_id = 0
   for s in suites:
     s.ReadStatusFile(variables)
     s.ReadTestCases(ctx)
     if len(args) > 0:
       s.FilterTestCasesByArgs(args)
     all_tests += s.tests
@@ skipping 60 matching lines @@
   exit_code = runner.Run(options.j)
   overall_duration = time.time() - start_time
 
   if options.time:
     verbose.PrintTestDurations(suites, overall_duration)
   return exit_code
 
 
 if __name__ == "__main__":
   sys.exit(Main())