RFR: 8157524 Revert JarFile methods "entries" and "stream" to Java 8 behavior

[Steve Drach]

>> It’s used in two places, moving it to jarPackages won’t work, I think.  I also put a check in to see if it’s a multi-release jar.
> I meant to move the method down to where jarPackages is located. I would probably adjust the comment too but we can do that once your changes are in jdk9/dev as we have several patches that will change this code. So I think what you have is okay.

Okay.  Will do.