Remove bitrig support

See rust-lang/rust#60775 .

Author: gnzlbg

ci/build.sh

@@ -199,7 +199,6 @@ thumbv7neon-linux-androideabi \
 thumbv7neon-unknown-linux-gnueabihf \
 thumbv8m.main-none-eabi \
 x86_64-pc-windows-msvc
-x86_64-unknown-bitrig \
 x86_64-unknown-dragonfly \
 x86_64-unknown-haiku \
 x86_64-unknown-hermit \

src/unix/bsd/mod.rs

@@ -663,8 +663,7 @@ cfg_if! {
     if #[cfg(any(target_os = "macos", target_os = "ios"))] {
         mod apple;
         pub use self::apple::*;
-    } else if #[cfg(any(target_os = "openbsd", target_os = "netbsd",
-                        target_os = "bitrig"))] {
+    } else if #[cfg(any(target_os = "openbsd", target_os = "netbsd"))] {
         mod netbsdlike;
         pub use self::netbsdlike::*;
     } else if #[cfg(any(target_os = "freebsd", target_os = "dragonfly"))] {

src/unix/bsd/netbsdlike/mod.rs

@@ -676,7 +676,7 @@ cfg_if! {
     if #[cfg(target_os = "netbsd")] {
         mod netbsd;
         pub use self::netbsd::*;
-    } else if #[cfg(any(target_os = "openbsd", target_os = "bitrig"))] {
+    } else if #[cfg(target_os = "openbsd")] {
         mod openbsdlike;
         pub use self::openbsdlike::*;
     } else {

src/unix/bsd/netbsdlike/openbsdlike/bitrig/mod.rs

@@ -939,9 +939,6 @@ cfg_if! {
     if #[cfg(target_os = "openbsd")] {
         mod openbsd;
         pub use self::openbsd::*;
-    } else if #[cfg(target_os = "bitrig")] {
-        mod bitrig;
-        pub use self::bitrig::*;
     } else {
         // Unknown target_os
     }

src/unix/bsd/netbsdlike/openbsdlike/bitrig/x86.rs

@@ -327,8 +327,7 @@ cfg_if! {
     } else if #[cfg(any(target_os = "macos",
                         target_os = "ios",
                         target_os = "android",
-                        target_os = "openbsd",
-                        target_os = "bitrig"))] {
+                        target_os = "openbsd"))] {
         #[link(name = "c")]
         #[link(name = "m")]
         extern {}
@@ -1158,8 +1157,7 @@ cfg_if! {
                         target_os = "freebsd",
                         target_os = "dragonfly",
                         target_os = "openbsd",
-                        target_os = "netbsd",
-                        target_os = "bitrig"))] {
+                        target_os = "netbsd"))] {
         mod bsd;
         pub use self::bsd::*;
     } else if #[cfg(any(target_os = "solaris",