Auto merge of #2958 - thomcc:tvos-support, r=JohnTitor

Add support for tvOS

This is essentially identical to the iOS support, as the OS is... essentially identical to iOS.

Author: bors

src/unix/bsd/mod.rs

@@ -37,6 +37,7 @@ s! {
 
         #[cfg(not(any(target_os = "macos",
                       target_os = "ios",
+                      target_os = "tvos",
                       target_os = "watchos",
                       target_os = "netbsd",
                       target_os = "openbsd")))]
@@ -887,7 +888,7 @@ extern "C" {
 }
 
 cfg_if! {
-    if #[cfg(any(target_os = "macos", target_os = "ios", target_os = "watchos"))] {
+    if #[cfg(any(target_os = "macos", target_os = "ios", target_os = "tvos", target_os = "watchos"))] {
         mod apple;
         pub use self::apple::*;
     } else if #[cfg(any(target_os = "openbsd", target_os = "netbsd"))] {

src/unix/mod.rs

@@ -356,6 +356,7 @@ cfg_if! {
         extern {}
     } else if #[cfg(any(target_os = "macos",
                         target_os = "ios",
+                        target_os = "tvos",
                         target_os = "watchos",
                         target_os = "android",
                         target_os = "openbsd"))] {
@@ -1030,7 +1031,12 @@ extern "C" {
     pub fn getrusage(resource: ::c_int, usage: *mut rusage) -> ::c_int;
 
     #[cfg_attr(
-        any(target_os = "macos", target_os = "ios", target_os = "watchos"),
+        any(
+            target_os = "macos",
+            target_os = "ios",
+            target_os = "tvos",
+            target_os = "watchos"
+        ),
         link_name = "realpath$DARWIN_EXTSN"
     )]
     pub fn realpath(pathname: *const ::c_char, resolved: *mut ::c_char) -> *mut ::c_char;
@@ -1197,7 +1203,12 @@ extern "C" {
         link_name = "__res_init"
     )]
     #[cfg_attr(
-        any(target_os = "macos", target_os = "ios", target_os = "watchos"),
+        any(
+            target_os = "macos",
+            target_os = "ios",
+            target_os = "tvos",
+            target_os = "watchos"
+        ),
         link_name = "res_9_init"
     )]
     pub fn res_init() -> ::c_int;
@@ -1483,6 +1494,7 @@ cfg_if! {
         pub use self::linux_like::*;
     } else if #[cfg(any(target_os = "macos",
                         target_os = "ios",
+                        target_os = "tvos",
                         target_os = "watchos",
                         target_os = "freebsd",
                         target_os = "dragonfly",