libextra: Fix even more merge fallout.

src/libextra/ebml.rs

@@ -94,7 +94,6 @@ pub mod reader {
 
     use serialize;
 
-    use core::prelude::*;
     use core::cast::transmute;
     use core::int;
     use core::io;
@@ -106,6 +105,8 @@ pub mod reader {
 
     #[cfg(target_arch = "x86")]
     #[cfg(target_arch = "x86_64")]
+    use core::option::{None, Option, Some};
+    use core::ptr::offset;
     use core::unstable::intrinsics::bswap32;
 
     // ebml reading

src/libextra/num/bigint.rs

@@ -382,8 +382,6 @@ impl Integer for BigUint {
             while m >= b {
                 let (d0, d_unit, b_unit) = div_estimate(&m, &b, n);
                 let mut d0 = d0;
-                let mut d_unit = d_unit;
-                let mut b_unit = b_unit;
                 let mut prod = b * d0;
                 while prod > m {
                     // FIXME(#6050): overloaded operators force moves with generic types

src/libextra/test.rs

@@ -751,9 +751,6 @@ impl BenchHarness {
 }
 
 pub mod bench {
-    use core::prelude::*;
-
-    use core::vec;
     use test::{BenchHarness, BenchSamples};
 
     pub fn benchmark(f: &fn(&mut BenchHarness)) -> BenchSamples {

src/libextra/timer.rs

@@ -125,7 +125,6 @@ pub fn recv_timeout<T:Copy + Send>(iotask: &IoTask,
                                    -> Option<T> {
     let (timeout_po, timeout_ch) = stream::<()>();
     let mut timeout_po = timeout_po;
-    let mut timeout_ch = timeout_ch;
     delayed_send(iotask, msecs, &timeout_ch, ());
 
     // XXX: Workaround due to ports and channels not being &mut. They should

src/libstd/task/spawn.rs

@@ -637,7 +637,6 @@ fn spawn_raw_oldsched(mut opts: TaskOpts, f: ~fn()) {
         let result: ~fn() = || {
             // Agh. Get move-mode items into the closure. FIXME (#2829)
             let (notify_chan, child_arc, ancestors) = child_data.take();
-            let mut child_arc = child_arc;
             let mut ancestors = ancestors;
             // Child task runs this code.