update cfg(bootstrap)

compiler/rustc_data_structures/src/flock.rs

@@ -4,31 +4,6 @@
 //! green/native threading. This is just a bare-bones enough solution for
 //! librustdoc, it is not production quality at all.
 
-#[cfg(bootstrap)]
-cfg_match! {
-    cfg(target_os = "linux") => {
-        mod linux;
-        use linux as imp;
-    }
-    cfg(target_os = "redox") => {
-        mod linux;
-        use linux as imp;
-    }
-    cfg(unix) => {
-        mod unix;
-        use unix as imp;
-    }
-    cfg(windows) => {
-        mod windows;
-        use self::windows as imp;
-    }
-    _ => {
-        mod unsupported;
-        use unsupported as imp;
-    }
-}
-
-#[cfg(not(bootstrap))]
 cfg_match! {
     target_os = "linux" => {
         mod linux;