Bug 1772638 - make nsJSContext::MaybePokeGC trigger EAGER_ALLOC_TRIGGER major GCs

Differential Revision: https://phabricator.services.mozilla.com/D152950

dom/base/nsJSEnvironment.cpp

@@ -1703,10 +1703,10 @@ void nsJSContext::MaybePokeGC() {
     MOZ_ASSERT(reason == JS::GCReason::EAGER_NURSERY_COLLECTION);
     sScheduler.PokeMinorGC(reason);
   }
-
-  // Bug 1772638: For now, only do eager minor GCs. Eager major GCs regress some
-  // benchmarks. Hopefully that will be worked out and this will check for
-  // whether an eager major GC is needed.
+  reason = JS::WantEagerMajorGC(rt);
+  if (reason != JS::GCReason::NO_REASON) {
+    PokeGC(reason, nullptr, 0);
+  }
 }
 
 void nsJSContext::DoLowMemoryGC() {