Rollup merge of #81940 - jhpratt:stabilize-str_split_once, r=m-ou-se

Stabilize str_split_once

Closes #74773

compiler/rustc_codegen_cranelift/src/lib.rs

@@ -5,8 +5,7 @@
     associated_type_bounds,
     never_type,
     try_blocks,
-    hash_drain_filter,
-    str_split_once
+    hash_drain_filter
 )]
 #![warn(rust_2018_idioms)]
 #![warn(unused_lifetimes)]

compiler/rustc_mir/src/lib.rs

@@ -28,7 +28,6 @@ Rust MIR: a lowered representation of Rust.
 #![feature(or_patterns)]
 #![feature(once_cell)]
 #![feature(control_flow_enum)]
-#![feature(str_split_once)]
 #![recursion_limit = "256"]
 
 #[macro_use]

compiler/rustc_session/src/lib.rs

@@ -1,7 +1,6 @@
 #![feature(crate_visibility_modifier)]
 #![feature(once_cell)]
 #![feature(or_patterns)]
-#![feature(str_split_once)]
 
 #[macro_use]
 extern crate bitflags;

compiler/rustc_span/src/lib.rs

@@ -22,7 +22,6 @@
 #![feature(nll)]
 #![feature(min_specialization)]
 #![feature(option_expect_none)]
-#![feature(str_split_once)]
 
 #[macro_use]
 extern crate rustc_macros;

compiler/rustc_target/src/lib.rs

@@ -15,7 +15,6 @@
 #![feature(never_type)]
 #![feature(associated_type_bounds)]
 #![feature(exhaustive_patterns)]
-#![feature(str_split_once)]
 
 #[macro_use]
 extern crate rustc_macros;