Stabilize Command::envs

Closes rust-lang#38526

Author: sfackler

Diff for: src/librustc_trans/lib.rs

@@ -35,7 +35,6 @@
 #![feature(slice_patterns)]
 #![feature(unicode)]
 #![feature(conservative_impl_trait)]
-#![feature(command_envs)]
 
 #![cfg_attr(stage0, unstable(feature = "rustc_private", issue = "27812"))]
 #![cfg_attr(stage0, feature(rustc_private))]

Diff for: src/libstd/process.rs

@@ -440,8 +440,6 @@ impl Command {
     /// Basic usage:
     ///
     /// ```no_run
-    /// #![feature(command_envs)]
-    ///
     /// use std::process::{Command, Stdio};
     /// use std::env;
     /// use std::collections::HashMap;
@@ -459,7 +457,7 @@ impl Command {
     ///         .spawn()
     ///         .expect("printenv failed to start");
     /// ```
-    #[unstable(feature = "command_envs", issue = "38526")]
+    #[stable(feature = "command_envs", since = "1.19.0")]
     pub fn envs<I, K, V>(&mut self, vars: I) -> &mut Command
         where I: IntoIterator<Item=(K, V)>, K: AsRef<OsStr>, V: AsRef<OsStr>
     {

Diff for: src/test/run-pass/process-envs.rs

@@ -10,8 +10,6 @@
 
 // ignore-emscripten
 
-#![feature(command_envs)]
-
 use std::process::Command;
 use std::env;
 use std::collections::HashMap;