std.Build.Step: split evalChildProcess into two functions
Now there is `captureChildProcess` which gives access to the
`std.process.Child.RunResult`, which is useful for accessing the stdout.
It also accepts and passes an optional `std.Progress.Node` to the child.
af7afbd08bAndrew Kelley committed on 6/17/2024, 2:29:05 AMparent42658de