[MB] Add concurrent marking bots

Add configs for:
https://chromium-review.googlesource.com/c/508349

NOTRY=true
TBR=ulan@chromium.org

Bug: chromium:723600
Change-Id: Ie0be3d34cc35a72c012c601d0bf8c8b707e69f32
Reviewed-on: https://chromium-review.googlesource.com/508628
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45396}

infra/mb/mb_config.pyl

@@ -84,6 +84,8 @@
       # Sanitizers.
       'V8 Linux64 ASAN': 'gn_release_x64_asan',
       'V8 Linux64 TSAN': 'gn_release_x64_tsan',
+      'V8 Linux64 TSAN - concurrent marking':
+          'gn_release_x64_tsan_concurrent_marking',
       'V8 Linux - arm64 - sim - MSAN': 'gn_release_simulate_arm64_msan',
       # Clusterfuzz.
       'V8 Linux64 - release builder': 'gn_release_x64_correctness_fuzzer',
@@ -189,6 +191,8 @@
       'v8_linux64_sanitizer_coverage_rel':
           'gyp_release_x64_asan_minimal_symbols_coverage',
       'v8_linux64_tsan_rel': 'gn_release_x64_tsan_minimal_symbols',
+      'v8_linux64_tsan_concurrent_marking_rel_ng':
+          'gn_release_x64_tsan_concurrent_marking_minimal_symbols',
       'v8_win_dbg': 'gn_debug_x86_trybot',
       'v8_win_compile_dbg': 'gn_debug_x86_trybot',
       'v8_win_rel_ng': 'gn_release_x86_trybot',
@@ -363,6 +367,12 @@
       'gn', 'release_trybot', 'x64', 'swarming'],
     'gn_release_x64_tsan': [
       'gn', 'release_bot', 'x64', 'tsan', 'swarming'],
+    'gn_release_x64_tsan_concurrent_marking': [
+      'gn', 'release_bot', 'x64', 'v8_enable_concurrent_marking', 'tsan',
+      'swarming'],
+    'gn_release_x64_tsan_concurrent_marking_minimal_symbols': [
+      'gn', 'release_bot', 'x64', 'v8_enable_concurrent_marking', 'tsan',
+      'minimal_symbols', 'swarming'],
     'gn_release_x64_tsan_minimal_symbols': [
       'gn', 'release_bot', 'x64', 'tsan', 'minimal_symbols', 'swarming'],
     'gn_release_x64_valgrind': [
@@ -700,6 +710,10 @@
       'gyp_defines': 'v8_enable_i18n_support=0 icu_use_data_file_flag=0',
     },
 
+    'v8_enable_concurrent_marking': {
+      'gn_args': 'v8_enable_concurrent_marking=true',
+    },
+
     'v8_correctness_fuzzer': {
       'gn_args': 'v8_correctness_fuzzer=true v8_multi_arch_build=true',
     },