Migrate v8_linux64_msan_rel to next-gen format

This CL splits the v8_linux64_msan_rel
to an intitial buidler and a triggered
builder with changing the name to a
new format (master side).

Bug: v8:10445
Change-Id: I42a975a30a5210c96acb27b18fc1ac7de7c0ecd1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2202990Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Almothana Athamneh <almuthanna@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67830}

infra/mb/mb_config.pyl

@@ -232,6 +232,7 @@
       'v8_linux64_asan_rel_ng': 'release_x64_asan_minimal_symbols',
       'v8_linux64_cfi_rel_ng': 'release_x64_cfi',
       'v8_linux64_msan_rel': 'release_simulate_arm64_msan_minimal_symbols',
+      'v8_linux64_msan_rel_ng': 'release_simulate_arm64_msan_minimal_symbols',
       'v8_linux64_sanitizer_coverage_rel':
           'release_x64_asan_minimal_symbols_coverage',
       'v8_linux64_tsan_rel': 'release_x64_tsan_minimal_symbols',

infra/testing/builders.pyl

@@ -330,6 +330,15 @@
       {'name': 'v8testing', 'shards': 5},
     ],
   },
+  'v8_linux64_msan_rel_ng_triggered': {
+    'swarming_dimensions' : {
+      'os': 'Ubuntu-16.04',
+    },
+    'tests': [
+      {'name': 'test262', 'variant': 'default', 'shards': 2},
+      {'name': 'v8testing', 'shards': 5},
+    ],
+  },
   'v8_linux64_nodcheck_rel_ng_triggered': {
     'swarming_dimensions' : {
       'cpu': 'x86-64-avx2',