Revert "more cfg alias targets (#2236)" (#2237)

This reverts commit e13a182.

Author: SteveLauC

build.rs

@@ -6,14 +6,11 @@ fn main() {
         dragonfly: { target_os = "dragonfly" },
         ios: { target_os = "ios" },
         freebsd: { target_os = "freebsd" },
-        fuchsia: { target_os = "fuchsia" },
-        haiku: { target_os = "haiku" },
         illumos: { target_os = "illumos" },
         linux: { target_os = "linux" },
         macos: { target_os = "macos" },
         netbsd: { target_os = "netbsd" },
         openbsd: { target_os = "openbsd" },
-        redox: { target_os = "redox" },
         solaris: { target_os = "solaris" },
         watchos: { target_os = "watchos" },
         tvos: { target_os = "tvos" },

src/lib.rs

@@ -92,7 +92,6 @@
 #![cfg_attr(docsrs, feature(doc_cfg))]
 #![deny(clippy::cast_ptr_alignment)]
 #![deny(unsafe_op_in_unsafe_fn)]
-#![allow(clippy::mismatched_target_os)]
 
 // Re-exported external crates
 pub use libc;