8305206: Add @spec tags in java.base/java.* (part 1)

Reviewed-by: alanb, naoto, darcy, lancea, dfuchs, iris, mchung

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

@@ -1956,6 +1956,8 @@ public class Thread implements Runnable {
      * @param      name   the new name for this thread.
      * @throws     SecurityException  if the current thread cannot modify this
      *             thread.
+     *
+     * @spec jni/index.html Java Native Interface Specification
      * @see        #getName
      * @see        #checkAccess()
      */