Bug 1511411 - Add displaylist_mutate to raptor tests running on windows10-64-ux opt. r=rwood

Add displaylist_mutate and related tests to run on low end hardware

Differential Revision: https://phabricator.services.mozilla.com/D13598

--HG--
extra : moz-landing-system : lando

taskcluster/ci/test/test-platforms.yml

@@ -199,6 +199,7 @@ windows10-64-ux/opt:
     build-platform: win64-nightly/opt
     test-sets:
         - raptor-firefox
+        - talos-ux
 
 windows10-64-pgo/opt:
     build-platform: win64-pgo/opt

taskcluster/ci/test/test-sets.yml

@@ -76,6 +76,9 @@ talos:
     # - talos-h1 Bug 1487031 - Disabled for not finding actionable regressions
     # - talos-h2 Bug 1487031 - Disabled for not finding actionable regressions
 
+talos-ux:
+    - talos-g4
+
 raptor-firefox:
     - raptor-tp6-1-firefox
     - raptor-tp6-2-firefox