std: Rename io/path features with old_ prefix

This commit renames the features for the `std::old_io` and `std::old_path`
modules to `old_io` and `old_path` to help facilitate migration to the new APIs.

This is a breaking change as crates which mention the old feature names now need
to be renamed to use the new feature names.

[breaking-change]

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libgraphviz/lib.rs b/src/libgraphviz/lib.rs
index a1a271bc5ab..230deabee00 100644
--- a/src/libgraphviz/lib.rs
+++ b/src/libgraphviz/lib.rs
@@ -276,7 +276,7 @@
 #![feature(int_uint)]
 #![feature(collections)]
 #![feature(core)]
-#![feature(io)]
+#![feature(old_io)]
 
 use self::LabelText::*;