changes from feedback

library/std/build.rs

@@ -3,15 +3,11 @@ use std::env;
 fn main() {
     println!("cargo:rerun-if-changed=build.rs");
     let target = env::var("TARGET").expect("TARGET was not set");
-    if target.contains("freebsd") {
-        println!("cargo:rustc-cfg=freebsd12");
-        if env::var("RUST_STD_FREEBSD_13_ABI").is_ok() {
-            println!("cargo:rustc-cfg=freebsd13");
-        }
-    } else if target.contains("linux")
+    if target.contains("linux")
         || target.contains("netbsd")
         || target.contains("dragonfly")
         || target.contains("openbsd")
+        || target.contains("freebsd")
         || target.contains("solaris")
         || target.contains("illumos")
         || target.contains("apple-darwin")

library/std/src/os/freebsd/fs.rs

@@ -76,12 +76,7 @@ impl MetadataExt for Metadata {
     fn as_raw_stat(&self) -> &raw::stat {
         // The methods below use libc::stat, so they work fine when libc is built with FreeBSD 12 ABI.
         // This method would just return nonsense.
-        #[cfg(freebsd12)]
         panic!("as_raw_stat not supported with FreeBSD 12 ABI");
-        #[cfg(not(freebsd12))]
-        unsafe {
-            &*(self.as_inner().as_inner() as *const libc::stat as *const raw::stat)
-        }
     }
     fn st_dev(&self) -> u64 {
         self.as_inner().as_inner().st_dev as u64
@@ -143,12 +138,7 @@ impl MetadataExt for Metadata {
     fn st_flags(&self) -> u32 {
         self.as_inner().as_inner().st_flags as u32
     }
-    #[cfg(freebsd12)]
     fn st_lspare(&self) -> u32 {
         panic!("st_lspare not supported with FreeBSD 12 ABI");
     }
-    #[cfg(not(freebsd12))]
-    fn st_lspare(&self) -> u32 {
-        self.as_inner().as_inner().st_lspare as u32
-    }
 }