Revert "Allow unaligned references for Debug implementations"

This reverts commit 655c25b.

Author: chrysn

src/lib.rs

@@ -77,7 +77,6 @@
 #![allow(non_upper_case_globals)]
 #![allow(non_camel_case_types)]
 #![allow(non_snake_case)]
-#![warn(unaligned_references)]
 #![cfg_attr(feature = "keep-extern-types", feature(extern_types))]
 
 pub mod libc;