[PATCH] Cygwin: CI: cygstress: improve error handling and add verbose mode

[Christian Franke]

Christian Franke wrote:
>  A followup to:
> https://sourceware.org/pipermail/cygwin-patches/2025q2/013674.html
>

>  From b0a5ba548cc9041246b1d6396d16292c77399605 Mon Sep 17 00:00:00 2001
> From: Christian Franke<christian.franke@t-online.de>
> Date: Mon, 28 Apr 2025 14:32:34 +0200
> Subject: [PATCH] Cygwin: CI: cygstress: improve error handling and add verbose
>   mode
>
> Check for unexpected output (Cygwin error messages).  Combine multiple
> error findings into one FAILURE line per test.  Avoid a race in the
> watchdog process.  Print all outputs if the new -v option is used.

Pushed.