This commit cleans up a few test warnings

src/libstd/io/fs.rs

@@ -1282,10 +1282,10 @@ mod test {
     }
 
     iotest!(fn binary_file() {
-        use rand::{rng, Rng};
+        use rand::{Rng, task_rng};
 
         let mut bytes = [0, ..1024];
-        rng().fill_bytes(bytes);
+        task_rng().fill_bytes(bytes);
 
         let tmpdir = tmpdir();
 

src/libstd/rt/args.rs

@@ -66,7 +66,6 @@ mod imp {
     use cast;
     use clone::Clone;
     use option::{Option, Some, None};
-    use ptr::RawPtr;
     use iter::Iterator;
     use unstable::mutex::{StaticNativeMutex, NATIVE_MUTEX_INIT};
     use mem;
@@ -124,6 +123,7 @@ mod imp {
     #[cfg(not(test))]
     unsafe fn load_argc_and_argv(argc: int, argv: **u8) -> ~[~[u8]] {
         use c_str::CString;
+        use ptr::RawPtr;
         use {slice, libc};
         use slice::CloneableVector;
 

src/libstd/rt/task.rs

@@ -433,8 +433,8 @@ mod test {
 
     #[test]
     fn rng() {
-        use rand::{rng, Rng};
-        let mut r = rng();
+        use rand::{Rng, task_rng};
+        let mut r = task_rng();
         let _ = r.next_u32();
     }
 

src/libstd/vec.rs

@@ -1365,7 +1365,6 @@ mod tests {
     use mem::{drop, size_of};
     use ops::Drop;
     use option::{Some, None};
-    use ptr;
     use container::Container;
     use slice::{Vector, MutableVector, ImmutableVector};