Stabilize termination_trait

This stabilizes `main` with non-() return types; see #48453.

src/test/compile-fail/rfc-1937-termination-trait/termination-trait-main-i32.rs

@@ -8,6 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-fn main() -> i32 { //~ ERROR main function has wrong type [E0580]
+fn main() -> i32 {
+//~^ ERROR the trait bound `i32: std::process::Termination` is not satisfied [E0277]
     0
 }

src/test/compile-fail/rfc-1937-termination-trait/termination-trait-main-wrong-type.rs

@@ -7,7 +7,6 @@
 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
-#![feature(termination_trait)]
 
 fn main() -> char {
 //~^ ERROR: the trait bound `char: std::process::Termination` is not satisfied

src/test/compile-fail/rfc-1937-termination-trait/termination-trait-not-satisfied.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(termination_trait)]
-
 struct ReturnType {}
 
 fn main() -> ReturnType { //~ ERROR `ReturnType: std::process::Termination` is not satisfied

src/test/run-fail/rfc-1937-termination-trait/termination-trait-for-never.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(termination_trait)]
-
 // error-pattern:oh, dear
 
 fn main() -> ! {

src/test/run-fail/rfc-1937-termination-trait/termination-trait-for-result-box-error_err.rs

@@ -11,8 +11,6 @@
 // must-compile-successfully
 // failure-status: 1
 
-#![feature(termination_trait)]
-
 use std::io::{Error, ErrorKind};
 
 fn main() -> Result<(), Box<Error>> {

src/test/run-pass/rfc-1937-termination-trait/termination-trait-for-empty.rs

@@ -8,6 +8,4 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(termination_trait)]
-
 fn main() {}

src/test/run-pass/rfc-1937-termination-trait/termination-trait-for-exitcode.rs

@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(termination_trait)]
 #![feature(process_exitcode_placeholder)]
 
 use std::process::ExitCode;

src/test/run-pass/rfc-1937-termination-trait/termination-trait-for-result-box-error_ok.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(termination_trait)]
-
 use std::io::Error;
 
 fn main() -> Result<(), Box<Error>> {

src/test/run-pass/rfc-1937-termination-trait/termination-trait-for-result.rs

@@ -8,8 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-#![feature(termination_trait)]
-
 use std::io::Error;
 
 fn main() -> Result<(), Error> {