8067801: Enforce null check for underlying I/O streams

[Brian Burkhalter]

Hi Lance,

> On Jul 17, 2019, at 1:55 PM, Lance Andersen <lance.andersen at oracle.com> wrote:
> 
> I guess the next question(here he goes again ;-)  is do you want to test all of the constructors such as BufferedInputStream(InputStream, int) or just one per class?  I realize the BufferedInputStream(InputStream) just calls into BufferedInputStream(InputStream, int).

Might as well add them in: http://cr.openjdk.java.net/~bpb/8067801/webrev.02/

> Sorry for  the continual questions and extra work 

No worries: it’s good to have things pointed out!

Thanks,

Brian