Stabilize assert_matches and move it to core::macros

Closes rust-lang#82775

This is a revive of rust-lang#120234, with the
suggested move from the public assert_matches module to macros. This
necessitates the rename of the internal macros modules to core_macros and
std_macros respectively.

Author: Voultapher

compiler/rustc_abi/src/extern_abi/tests.rs

@@ -1,4 +1,4 @@
-use std::assert_matches::assert_matches;
+use std::macros::assert_matches;
 use std::str::FromStr;
 
 use super::*;

compiler/rustc_abi/src/lib.rs

@@ -1,7 +1,6 @@
 // tidy-alphabetical-start
 #![cfg_attr(feature = "nightly", allow(internal_features))]
 #![cfg_attr(feature = "nightly", doc(rust_logo))]
-#![cfg_attr(feature = "nightly", feature(assert_matches))]
 #![cfg_attr(feature = "nightly", feature(rustc_attrs))]
 #![cfg_attr(feature = "nightly", feature(rustdoc_internals))]
 #![cfg_attr(feature = "nightly", feature(step_trait))]

compiler/rustc_ast_lowering/src/expr.rs

@@ -1,4 +1,4 @@
-use std::assert_matches::assert_matches;
+use std::macros::assert_matches;
 use std::ops::ControlFlow;
 use std::sync::Arc;
 

compiler/rustc_ast_lowering/src/lib.rs

@@ -33,7 +33,6 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![doc(rust_logo)]
-#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(if_let_guard)]
 #![feature(let_chains)]

compiler/rustc_borrowck/src/diagnostics/explain_borrow.rs

@@ -3,7 +3,7 @@
 #![allow(rustc::diagnostic_outside_of_impl)]
 #![allow(rustc::untranslatable_diagnostic)]
 
-use std::assert_matches::assert_matches;
+use std::macros::assert_matches;
 
 use rustc_errors::{Applicability, Diag, EmissionGuarantee};
 use rustc_hir as hir;

compiler/rustc_borrowck/src/lib.rs

@@ -3,7 +3,6 @@
 // tidy-alphabetical-start
 #![allow(internal_features)]
 #![doc(rust_logo)]
-#![feature(assert_matches)]
 #![feature(box_patterns)]
 #![feature(file_buffered)]
 #![feature(if_let_guard)]

compiler/rustc_borrowck/src/type_check/input_output.rs

@@ -7,7 +7,7 @@
 //! `RETURN_PLACE` the MIR arguments) are always fully normalized (and
 //! contain revealed `impl Trait` values).
 
-use std::assert_matches::assert_matches;
+use std::macros::assert_matches;
 
 use itertools::Itertools;
 use rustc_hir as hir;

compiler/rustc_builtin_macros/src/lib.rs

@@ -7,7 +7,6 @@
 #![allow(rustc::untranslatable_diagnostic)]
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![doc(rust_logo)]
-#![feature(assert_matches)]
 #![feature(autodiff)]
 #![feature(box_patterns)]
 #![feature(decl_macro)]

compiler/rustc_builtin_macros/src/test.rs

@@ -1,8 +1,8 @@
 //! The expansion from a test function to the appropriate test struct for libtest
 //! Ideally, this code would be in libtest but for efficiency and error messages it lives here.
 
-use std::assert_matches::assert_matches;
 use std::iter;
+use std::macros::assert_matches;
 
 use rustc_ast::ptr::P;
 use rustc_ast::{self as ast, GenericParamKind, attr};

compiler/rustc_codegen_llvm/src/asm.rs

@@ -1,4 +1,4 @@
-use std::assert_matches::assert_matches;
+use std::macros::assert_matches;
 
 use libc::{c_char, c_uint};
 use rustc_abi::{BackendRepr, Float, Integer, Primitive, Scalar};