ObjectMethods::bootstrap should specify NPE if any argument except lookup is null

NullPointerException is thrown by ObjectMethods::bootstrap if any of the arguments except `names` is null but @throws NPE is missing in the spec

Note: according to test (test/jdk/java/lang/runtime/ObjectMethodsTest.java) the only argument that can be null without a NPE being generated is `lookup` which is actually ignored inside of the method's body