V8 Buildbot: Update gatekeeper.

scripts/slave/gatekeeper.json

 {
   "comment": ["This is a configuration file for gatekeeper_ng.py",
               "Look at that for documentation on this file's format."],
 
   "masters": {
     "https://build.chromium.org/p/chromium": [
       {
         "categories": [
           "chromium_tree_closer"
         ],
@@ skipping 822 matching lines @@
         "runhooks",
         "webkit_unit_tests",
         "Presubmit",
         "Static-Initializers",
         "Check",
         "Unittests",
         "OptimizeForSize",
         "Mjsunit",
         "Webkit",
         "Benchmarks",
+        "SimdJs - all",
+        "SimdJs - small",
         "Test262",
+        "Test262 - no variants",
         "Test262-es6",
+        "Test262-es6 - no variants",
         "Mozilla",
         "GCMole arm",
         "GCMole arm64",
         "GCMole ia32",
         "GCMole x64",
         "Simple Leak Check"
       ],
       "forgiving_optional": [
         "bot_update",
         "package build",
@@ skipping 13 matching lines @@
       "forgiving_optional": [
         "svnkill",
         "taskkill"
       ],
       "closing_optional": [
         "compile"
       ]
     }
   }
 }