libcore: Remove as_bytes_slice

src/libcore/str.rs

@@ -24,6 +24,7 @@
 
    // Reinterpretation
    as_bytes,
+   as_bytes_slice,
    as_buf,
    as_c_str,
 
@@ -1751,6 +1752,10 @@ fn is_alphanumeric(s: &str) -> bool {
     }
 }
 
+pure fn as_bytes_slice(s: &a/str) -> &a/[u8] {
+    unsafe { ::unsafe::reinterpret_cast(&s) }
+}
+
 /**
  * Work with the byte buffer of a string as a null-terminated C string.
  *