std: Remove #[allow] directives in sys modules

These were suppressing lots of interesting warnings! Turns out there was also
quite a bit of dead code.

1 files changed, 4 insertions, 7 deletions

diff --git a/src/libstd/sys/windows/backtrace.rs b/src/libstd/sys/windows/backtrace.rs
index 51cf3032423..8de2fe1336f 100644
--- a/src/libstd/sys/windows/backtrace.rs
+++ b/src/libstd/sys/windows/backtrace.rs
@@ -24,19 +24,16 @@
 
 #![allow(dead_code)]
 
+use prelude::v1::*;
+
 use dynamic_lib::DynamicLibrary;
 use ffi::CStr;
 use intrinsics;
-use old_io::{IoResult, Writer};
+use old_io::IoResult;
 use libc;
 use mem;
-use ops::Drop;
-use option::Option::{Some};
-use old_path::Path;
 use ptr;
-use result::Result::{Ok, Err};
-use slice::SliceExt;
-use str::{self, StrExt};
+use str;
 use sync::{StaticMutex, MUTEX_INIT};
 
 use sys_common::backtrace::*;