ICE when converting std::run::process_status() to generic function

[lilyball]

If I convert std::run::process_status() to a generic function, parameterized by <S: Str>, as part of PR #8203, the snapshot compiler complains with

error: internal compiler error: encode_symbol: id not found 230917

Since I compiled libstd at stage2 just fine, I'm assuming that the next snapshot will cause this problem to go away.

[lilyball]

Nevermind. I wrote this issue so I could leave a // FIXME, but instead I'm going with #[cfg(stage0)].

[lilyball]

Now I'm getting the ICE in stage2 too. It worked with make check-stage2-std NO_REBUILD=1, so maybe it only works when tests are on? Which doesn't make any sense.

[lilyball]

The function looks like this:

pub fn process_status<S: Str>(prog: &str, args: &[S]) -> int {
    let mut prog = Process::new(prog, args, ProcessOptions {
        env: None,
        dir: None,
        in_fd: Some(0),
        out_fd: Some(1),
        err_fd: Some(2)
    }).unwrap();
    prog.finish()
}

Unlike the other issues that seem to emit this error, there's no internal static.

[lilyball]

Fixed with #8843.