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

BUG=none
R=machenbach@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/781763002

Cr-Commit-Position: refs/heads/master@{#25675}

tools/run-deopt-fuzzer.py

@@ -160,6 +160,9 @@ def BuildOptions():
   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("--command-prefix",
                     help="Prepended to each shell command used to run a test",
                     default="")
@@ -390,6 +393,7 @@ def Execute(arch, mode, args, options, suites, workspace):
     "system": utils.GuessOS(),
     "tsan": False,
     "msan": False,
+    "dcheck_always_on": options.dcheck_always_on,
   }
   all_tests = []
   num_tests = 0

tools/run-tests.py

@@ -141,6 +141,9 @@ def BuildOptions():
   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",
@@ -508,6 +511,7 @@ def Execute(arch, mode, args, options, suites, workspace):
     "system": utils.GuessOS(),
     "tsan": options.tsan,
     "msan": options.msan,
+    "dcheck_always_on": options.dcheck_always_on,
   }
   all_tests = []
   num_tests = 0