syntax: Implement #![no_core]

This commit is an implementation of [RFC 1184][rfc] which tweaks the behavior of
the `#![no_std]` attribute and adds a new `#![no_core]` attribute. The
`#![no_std]` attribute now injects `extern crate core` at the top of the crate
as well as the libcore prelude into all modules (in the same manner as the
standard library's prelude). The `#![no_core]` attribute disables both std and
core injection.

[rfc]: https://github.com/rust-lang/rfcs/pull/1184

1 files changed, 1 insertions, 0 deletions

diff --git a/src/libstd/sys/unix/ext/process.rs b/src/libstd/sys/unix/ext/process.rs
index 63adae17581..71f83e7404b 100644
--- a/src/libstd/sys/unix/ext/process.rs
+++ b/src/libstd/sys/unix/ext/process.rs
@@ -14,6 +14,7 @@
 
 use os::unix::raw::{uid_t, gid_t};
 use os::unix::io::{FromRawFd, RawFd, AsRawFd, IntoRawFd};
+#[cfg(stage0)]
 use prelude::v1::*;
 use process;
 use sys;