fix warnings

src/libcore/rt/stack.rs

@@ -31,9 +31,7 @@ pub impl StackSegment {
 
     /// Point one word beyond the high end of the allocated stack
     fn end(&self) -> *uint {
-        unsafe {
-            vec::raw::to_ptr(self.buf).offset(self.buf.len()) as *uint
-        }
+        vec::raw::to_ptr(self.buf).offset(self.buf.len()) as *uint
     }
 }
 

src/libcore/rt/uv/mod.rs

@@ -362,7 +362,7 @@ pub type Buf = uvll::uv_buf_t;
 
 /// Borrow a slice to a Buf
 pub fn slice_to_uv_buf(v: &[u8]) -> Buf {
-    let data = unsafe { vec::raw::to_ptr(v) };
+    let data = vec::raw::to_ptr(v);
     unsafe { uvll::buf_init(data, v.len()) }
 }
 

src/librustc/util/enum_set.rs

@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+#[cfg(stage0)]
 use core;
 
 #[deriving(Eq, IterBytes)]