Bogus exit code 127 from a child process

[Alexey Izbyshev]

Hello,

I've been getting occasional "Error 127" from make -jN on seemingly 
random jobs. After reducing the set of jobs and eventually eliminating 
make, I've arrived to this one-liner:

bash -c 'true & true & wait -n || echo 1: $? && wait -n || echo 2: $?'

When run repeatedly, the second "wait -n" often reports 127.

I've reproduced this in the following environments:

* Cygwin 3.5.1, Windows 10 22H2 x64
* Cygwin 3.4.6, Windows 10 22H2 x64 and Windows 7 x64

I couldn't reproduce it in Cygwin 3.3.6 (WOW64) on Windows 7 x64.

Thanks,
Alexey