Bug 1020800 - Check for correct thread after checking if GC is suppressed. (r=terrence)

js/src/gc/Nursery.cpp

@@ -736,11 +736,11 @@ CheckHashTablesAfterMovingGC(JSRuntime *rt)
 void
 js::Nursery::collect(JSRuntime *rt, JS::gcreason::Reason reason, TypeObjectList *pretenureTypes)
 {
-    JS_AbortIfWrongThread(rt);
-
     if (rt->mainThread.suppressGC)
         return;
 
+    JS_AbortIfWrongThread(rt);
+
     if (!isEnabled())
         return;