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* Lots of core prelude imports removed
* Makefile support for MSVC env vars and Rust crates removed
* Makefile support for morestack removed

src/libstd/io/cursor.rs

@@ -292,9 +292,6 @@ impl Write for Cursor<Vec<u8>> {
 
 #[cfg(test)]
 mod tests {
-    #[cfg(stage0)]
-    use core::prelude::v1::*;
-
     use io::prelude::*;
     use io::{Cursor, SeekFrom};
     use vec::Vec;