libstd: set baseline stability levels.

Earlier commits have established a baseline of `experimental` stability
for all crates under the facade (so their contents are considered
experimental within libstd). Since `experimental` is `allow` by
default, we should use the same baseline stability for libstd itself.

This commit adds `experimental` tags to all of the modules defined in
`std`, and `unstable` to `std` itself.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/libstd/failure.rs b/src/libstd/failure.rs
index d1552f0bd10..47ff85e2806 100644
--- a/src/libstd/failure.rs
+++ b/src/libstd/failure.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#![experimental]
+
 use alloc::owned::Box;
 use any::{Any, AnyRefExt};
 use fmt;