Rollup merge of #3540 - matthiaskrgr:rustup, r=flip1995

flip1995 · web-flow · commit b7a431ea1ddb · 2018-12-12T18:17:01.000+01:00
rustup #56092 fix ui test cast_alignment failure by adding #![feature(rustc_private)]
diff --git a/tests/ui/cast_alignment.rs b/tests/ui/cast_alignment.rs
@@ -9,8 +9,8 @@
 
 //! Test casts for alignment issues
 
-#![feature(libc)]
 
+#![feature(rustc_private)]
 extern crate libc;
 
 #[warn(clippy::cast_ptr_alignment)]
