Use <iostream> instead of <iostream.h> in Example Code for PCH

[TedLyngmo]

This old header seems to have been forgotten in one of the example files (UNSTABLE.H).

[PRMerger6]

@TedLyngmo : Thanks for your contribution! The author(s) have been notified to review your proposed change.

[jborsecnik]

I assume this is still in process. When you are done, please add a hash comment to indicate the action to take on this PR. Thanks.

[colin-home]

@TedLyngmo
Yes, I apologize for not commenting earlier. The header update is welcome; thanks for spotting that and contributing a change. I was working on getting the example to compile, and got the code looking okay with an added using statement, but ran into trouble with the makefile. It appears to be ancient, referring to libraries and command-line options that no longer exist. I thought I'd added a comment when I made an edit, but I may have gotten distracted while looking at the makefile problem. I'll take another look soon. Until then, I want to hold off on merging this. Thanks for your patience!

[TedLyngmo]

@corob-msft
No worries! Take your time. +1 on spotting the missing using statement.

@jborsecnik
I assume the hash comment link was for the MS staff?

[jborsecnik]

Yes. I wasn't sure if corob-msft's comment meant he was done with it. Thanks.

[PRMerger12]

@corob-msft : Thanks for your contribution! The author(s) have been notified to review your proposed change.

[colin-home]

@TedLyngmo Thanks for contributing. I'm going to adopt the change even though I haven't fixed the makefile yet, since I'm still hoping to get to that but haven't had time.