RFR: JDK-8226538: find-files.gmk gets corrupted if tab completion is used before running make first

[Tim Bell]

Erik:

> I'm changing TestMake.gmk to accept an
> input parameter for a target file to which the list of targets is
> printed to instead of stdout. This solves the fundamental design problem.

Sounds good.

> Bug: https://bugs.openjdk.java.net/browse/JDK-8226538
>
> Webrev: http://cr.openjdk.java.net/~erikj/8226538/webrev.01/

Looks good to me.

Tim