Auto merge of #45446 - leodasvacas:remove-libcollections, r=alexcrichton

Remove deprecated `collections` crate.

The real `collections` was merged with `alloc`, this facade was introduced [in this PR](https://github.com/rust-lang/rust/pull/42720) to give `#[no_std]` users time to adapt. This was done at least two cycles ago, now we can consider removing it for good.

src/Cargo.lock

@@ -321,14 +321,6 @@ dependencies = [
  "cc 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "collections"
-version = "0.0.0"
-dependencies = [
- "alloc 0.0.0",
- "core 0.0.0",
-]
-
 [[package]]
 name = "compiler_builtins"
 version = "0.0.0"
@@ -2137,7 +2129,6 @@ dependencies = [
  "alloc_jemalloc 0.0.0",
  "alloc_system 0.0.0",
  "build_helper 0.1.0",
- "collections 0.0.0",
  "compiler_builtins 0.0.0",
  "core 0.0.0",
  "libc 0.0.0",

src/bootstrap/dist.rs

@@ -738,7 +738,6 @@ impl Step for Src {
             "src/liballoc_jemalloc",
             "src/liballoc_system",
             "src/libbacktrace",
-            "src/libcollections",
             "src/libcompiler_builtins",
             "src/libcore",
             "src/liblibc",

src/bootstrap/doc.rs

@@ -490,7 +490,7 @@ impl Step for Std {
         // for which docs must be built.
         if !build.config.compiler_docs {
             cargo.arg("--no-deps");
-            for krate in &["alloc", "collections", "core", "std", "std_unicode"] {
+            for krate in &["alloc", "core", "std", "std_unicode"] {
                 cargo.arg("-p").arg(krate);
                 // Create all crate output directories first to make sure rustdoc uses
                 // relative links.

src/doc/unstable-book/src/library-features/collections.md

@@ -1,5 +0,0 @@
-# `collections`
-
-This feature is internal to the Rust compiler and is not intended for general use.
-
-------------------------

src/libcollections/Cargo.toml

@@ -1,12 +0,0 @@
-[package]
-authors = ["The Rust Project Developers"]
-name = "collections"
-version = "0.0.0"
-
-[lib]
-name = "collections"
-path = "lib.rs"
-
-[dependencies]
-alloc = { path = "../liballoc" }
-core = { path = "../libcore" }

src/libcollections/lib.rs

@@ -1,68 +0,0 @@
-// Copyright 2017 The Rust Project Developers. See the COPYRIGHT
-// file at the top-level directory of this distribution and at
-// http://rust-lang.org/COPYRIGHT.
-//
-// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
-// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
-// <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.
-
-#![allow(unused_attributes)]
-#![unstable(feature = "collections",
-            reason = "this library is unlikely to be stabilized in its current \
-                      form or name",
-            issue = "27783")]
-#![rustc_deprecated(since = "1.20.0",
-                    reason = "collections moved to `alloc`")]
-#![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
-       html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
-       html_root_url = "https://doc.rust-lang.org/nightly/",
-       issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
-       test(no_crate_inject, attr(allow(unused_variables), deny(warnings))))]
-#![no_std]
-#![deny(warnings)]
-
-#![feature(alloc)]
-#![feature(collections_range)]
-#![feature(macro_reexport)]
-#![feature(staged_api)]
-
-//! Collection types
-//!
-//! See [`std::collections`](../std/collections/index.html) for a detailed
-//! discussion of collections in Rust.
-
-#[macro_reexport(vec, format)]
-extern crate alloc;
-
-pub use alloc::Bound;
-
-pub use alloc::binary_heap;
-pub use alloc::borrow;
-pub use alloc::fmt;
-pub use alloc::linked_list;
-pub use alloc::range;
-pub use alloc::slice;
-pub use alloc::str;
-pub use alloc::string;
-pub use alloc::vec;
-pub use alloc::vec_deque;
-
-pub use alloc::btree_map;
-pub use alloc::btree_set;
-
-#[doc(no_inline)]
-pub use alloc::binary_heap::BinaryHeap;
-#[doc(no_inline)]
-pub use alloc::btree_map::BTreeMap;
-#[doc(no_inline)]
-pub use alloc::btree_set::BTreeSet;
-#[doc(no_inline)]
-pub use alloc::linked_list::LinkedList;
-#[doc(no_inline)]
-pub use alloc::vec_deque::VecDeque;
-#[doc(no_inline)]
-pub use alloc::string::String;
-#[doc(no_inline)]
-pub use alloc::vec::Vec;

src/libstd/Cargo.toml

@@ -15,7 +15,6 @@ alloc_jemalloc = { path = "../liballoc_jemalloc", optional = true }
 alloc_system = { path = "../liballoc_system" }
 panic_unwind = { path = "../libpanic_unwind", optional = true }
 panic_abort = { path = "../libpanic_abort" }
-collections = { path = "../libcollections" }
 core = { path = "../libcore" }
 libc = { path = "../rustc/libc_shim" }
 rand = { path = "../librand" }