Use $crate and macro reexport to reduce duplicated code

Many of libstd's macros are now re-exported from libcore and libcollections.
Their libstd definitions have moved to a macros_stage0 module and can disappear
after the next snapshot.

Where the two crates had already diverged, I took the libstd versions as
they're generally newer and better-tested. See e.g. d3c831b, which was a fix to
libstd's assert_eq!() that didn't make it into libcore's.

Fixes #16806.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/libstd/rand/os.rs b/src/libstd/rand/os.rs
index 6ae6a238c95..a79a6e35ebc 100644
--- a/src/libstd/rand/os.rs
+++ b/src/libstd/rand/os.rs
@@ -23,11 +23,14 @@ mod imp {
     use path::Path;
     use rand::Rng;
     use rand::reader::ReaderRng;
-    use result::Result::{Ok, Err};
+    use result::Result::Ok;
     use slice::SliceExt;
     use mem;
     use os::errno;
 
+    // NOTE: for old macros; remove after the next snapshot
+    #[cfg(stage0)] use result::Result::Err;
+
     #[cfg(all(target_os = "linux",
               any(target_arch = "x86_64",
                   target_arch = "x86",