Emscripten targets are Unix targets

[brson]

I suspect this will fix the errors compiling libc https://buildbot.rust-lang.org/builders/auto-linux-rustbuild-cross-opt/builds/689/steps/compile/logs/stdio that are occurring on every PR.

Emscripten is basically a posix emulation layer for the web and I consider it a Unix.

cc @alexcrichton

[rust-highfive]

r? @arielb1

(rust_highfive has picked a reviewer for you, use r? to override)

[brson]

I don't know how the error got onto master. It seems like bors would have caught that.

[sfackler]

@bors r+

[bors]

📌 Commit 31bda23 has been approved by sfackler

[nagisa]

Travis failed with some pretty relevant errors.

[tomaka]

Is there a possibility that it breaks code that does #[cfg(unix)] and #[cfg(emscripten)]?

[alexcrichton]

@bors: r+ p=1

[bors]

📌 Commit f262eea has been approved by alexcrichton

[bors]

⌛️ Testing commit f262eea with merge 5752eae...

[alexcrichton]

I don't know how the error got onto master. It seems like bors would have caught that.

Turns out we're not gating on the relevant builder in homu, we just haven't regressed it until now. Hurray!

[alexcrichton]

This passed on Travis and AppVeyor, merging manually