remove async_await feature gate

Signed-off-by: Yoshua Wuyts <yoshuawuyts@gmail.com>

Author: yoshuawuyts

benches/task_local.rs

@@ -1,5 +1,3 @@
-#![feature(async_await, test)]
-
 extern crate test;
 
 use async_std::task;

examples/hello-world.rs

@@ -1,7 +1,5 @@
 //! Spawns a task that says hello.
 
-#![feature(async_await)]
-
 use async_std::task;
 
 async fn say_hi() {

examples/line-count.rs

@@ -1,7 +1,5 @@
 //! Counts the number of lines in a file given as an argument.
 
-#![feature(async_await)]
-
 use std::env::args;
 
 use async_std::fs::File;

examples/list-dir.rs

@@ -1,7 +1,5 @@
 //! Lists files in a directory given as an argument.
 
-#![feature(async_await)]
-
 use std::env::args;
 
 use async_std::fs;

examples/logging.rs

@@ -1,7 +1,5 @@
 //! Prints the runtime's execution log on the standard output.
 
-#![feature(async_await)]
-
 use async_std::task;
 
 fn main() {

examples/print-file.rs

@@ -1,7 +1,5 @@
 //! Prints a file given as an argument to stdout.
 
-#![feature(async_await)]
-
 use std::env::args;
 
 use async_std::fs::File;

examples/stdin-echo.rs

@@ -1,7 +1,5 @@
 //! Echoes lines read on stdin to stdout.
 
-#![feature(async_await)]
-
 use async_std::io;
 use async_std::prelude::*;
 use async_std::task;

examples/stdin-timeout.rs

@@ -1,7 +1,5 @@
 //! Reads a line from stdin, or exits with an error if nothing is read in 5 seconds.
 
-#![feature(async_await)]
-
 use std::time::Duration;
 
 use async_std::io;

examples/surf-web.rs

@@ -1,7 +1,5 @@
 //! Sends an HTTP request to the Rust website.
 
-#![feature(async_await)]
-
 use async_std::task;
 
 fn main() -> Result<(), surf::Exception> {

examples/task-local.rs

@@ -1,7 +1,5 @@
 //! Creates a task-local value.
 
-#![feature(async_await)]
-
 use std::cell::Cell;
 
 use async_std::prelude::*;