remove #![feature(label_break_value)] from generated source code

Author: bungcip

c2rust-analyze/tests/filecheck/alloc.rs

@@ -1,5 +1,4 @@
 #![feature(extern_types)]
-#![feature(label_break_value)]
 #![feature(rustc_private)]
 #![feature(c_variadic)]
 #![allow(non_upper_case_globals)]

c2rust-refactor/src/lib.rs

@@ -5,7 +5,6 @@
     box_patterns,
     generator_trait,
     drain_filter,
-    label_break_value,
 )]
 #![cfg_attr(feature = "profile", feature(proc_macro_hygiene))]
 

c2rust-transpile/src/cfg/mod.rs

@@ -2072,7 +2072,6 @@ impl CfgBuilder {
             || !IncCleanup::new(in_tail, brk_lbl.clone()).remove_tail_expr(&mut stmts);
 
         if has_fallthrough && need_block && use_brk_lbl {
-            translator.use_feature("label_break_value");
             let block_body = mk().block(stmts);
             let block: Box<Expr> = mk().labelled_block_expr(block_body, brk_lbl.pretty_print());
             stmts = vec![mk().expr_stmt(block)]

c2rust-transpile/src/translator/mod.rs

@@ -4109,7 +4109,6 @@ impl<'c> Translation<'c> {
                             return Ok(WithStmts::new(stmts, val));
                         }
                         _ => {
-                            self.use_feature("label_break_value");
                             stmts.push(stmt)
                         }
                     }

examples/tinycc/translate.py

@@ -35,7 +35,6 @@
 MAIN_RS = os.path.join(RUST_SRC_DIR, "main.rs")
 # TODO(kkysen) shouldn't need `extern crate`
 MAIN_MODS = """\
-#![feature(label_break_value)]
 extern crate libc;
 pub mod i386_asm;
 pub mod libtcc;

examples/tmux/translate.py

@@ -56,7 +56,6 @@
 ]
 # TODO(kkysen) shouldn't need `extern crate`
 MAIN_MODS = """\
-#![feature(label_break_value)]
 #![allow(unused_imports)]
 extern crate libc;
 

tests/gotos/src/test_translation_only.rs

@@ -1,5 +1,3 @@
-//! feature_label_break_value
-
 use crate::jump_into_loop::rust_jump_into_loop;
 use crate::label_break_trigger::rust_triggers_label_break;