8271624: Avoid unnecessary ThreadGroup.checkAccess calls when creating Threads

Reviewed-by: rriggs

src/java.base/share/classes/java/lang/Thread.java

@@ -417,14 +417,14 @@ public class Thread implements Runnable {
             }
         }
 
-        /* checkAccess regardless of whether or not threadgroup is
-           explicitly passed in. */
-        g.checkAccess();
-
         /*
          * Do we have the required permissions?
          */
         if (security != null) {
+            /* checkAccess regardless of whether or not threadgroup is
+               explicitly passed in. */
+            security.checkAccess(g);
+
             if (isCCLOverridden(getClass())) {
                 security.checkPermission(
                         SecurityConstants.SUBCLASS_IMPLEMENTATION_PERMISSION);