Rollup merge of rust-lang#89898 - Amanieu:remove_alloc_prelude, r=joshtriplett

Remove alloc::prelude

As per the libs team decision in rust-lang#58935.

Closes rust-lang#58935

Author: matthiaskrgr

compiler/rustc_codegen_cranelift/example/alloc_example.rs

@@ -1,10 +1,10 @@
-#![feature(start, core_intrinsics, alloc_prelude, alloc_error_handler, box_syntax)]
+#![feature(start, core_intrinsics, alloc_error_handler, box_syntax)]
 #![no_std]
 
 extern crate alloc;
 extern crate alloc_system;
 
-use alloc::prelude::v1::*;
+use alloc::boxed::Box;
 
 use alloc_system::System;
 

compiler/rustc_codegen_gcc/example/alloc_example.rs

@@ -1,10 +1,10 @@
-#![feature(start, box_syntax, core_intrinsics, alloc_prelude, alloc_error_handler)]
+#![feature(start, box_syntax, core_intrinsics, alloc_error_handler)]
 #![no_std]
 
 extern crate alloc;
 extern crate alloc_system;
 
-use alloc::prelude::v1::*;
+use alloc::boxed::Box;
 
 use alloc_system::System;
 

library/alloc/src/lib.rs

@@ -189,7 +189,6 @@ mod boxed {
 pub mod borrow;
 pub mod collections;
 pub mod fmt;
-pub mod prelude;
 pub mod raw_vec;
 pub mod rc;
 pub mod slice;