Bug 1625134: Enable the compatibility panel in Nightly and DevEdition. r=Honza

Differential Revision: https://phabricator.services.mozilla.com/D72996

browser/app/profile/firefox.js

@@ -1959,7 +1959,11 @@ pref("devtools.inspector.showAllAnonymousContent", false);
 // Enable the new Rules View
 pref("devtools.inspector.new-rulesview.enabled", false);
 // Enable the compatibility tool in the inspector.
+#if defined(NIGHTLY_BUILD) || defined(MOZ_DEV_EDITION)
+pref("devtools.inspector.compatibility.enabled", true);
+#else
 pref("devtools.inspector.compatibility.enabled", false);
+#endif
 // Enable color scheme simulation in the inspector.
 pref("devtools.inspector.color-scheme-simulation.enabled", false);