Spec for PBEParameterSpec does not specify behavior when paramSpec is null

Spec for JEP-121 PBEParameterSpec(byte[] salt, int iterationCount, AlgorithmParameterSpec paramSpec) states that a NullPointerException is thrown if salt is null. It does not state the behavior if paramSpec is null.

New JCK 8 tests for PBEParamaeterSpec accept null as a valid input paramSpec value. It would be good to clarify that null is an acceptable value for ParamSpec in the API doc.