Bug 1565631 - Add an early return to Nursery::shouldCollect() r=sfink

Differential Revision: https://phabricator.services.mozilla.com/D38030

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

js/src/gc/Nursery.cpp

@@ -816,6 +816,10 @@ inline void js::Nursery::endProfile(ProfileKey key) {
 }
 
 bool js::Nursery::shouldCollect() const {
+  if (isEmpty()) {
+    return false;
+  }
+
   if (minorGCRequested()) {
     return true;
   }