Extend minicore with intrinsics and use it to replace #[rustc_intrinsic] in tests

[RalfJung]

We now have a "minicore" at tests/auxiliary/minicore.rs with some lang items to be shared among no_core tests. However, there's a lot more that could reasonably be added there, and this does not require a lot of experience with how rustc works so it could be a good first issue as well.

To find a candidate test, grep the test suite for #[rustc_intrinsic]. If this test also uses #![no_core], changes are high that this is a good candidate. If the test does not yet use minicore, first port it to minicore by adding //@ add-core-stubs and:

extern crate minicore;
use minicore::*;

See e.g. tests/assembly/simd-intrinsic-mask-reduce.rs for an example.
All of the existing lang items (things with #[lang] attributes) in the test should be removed now; if they don't yet exist in minicore, they should be added there. Then also remove the #[rustc_intrinsic] declarations from the test and add them to minicore if they do not yet exist there.

Cc @jieyouxu

[hbina]

After applying the change to this test https://github.com/rust-lang/rust/blob/master/tests/assembly/rust-abi-arg-attr.rs
It fails,

error[E0425]: cannot find function `three_way_compare` in this scope
  --> /home/hbina085/git/rustlang/tests/assembly/rust-abi-arg-attr.rs:24:15
   |
24 |         match three_way_compare($a, $b) {
   |               ^^^^^^^^^^^^^^^^^ not found in this scope
...
68 |     max!(a, b)
   |     ---------- in this macro invocation
   |
   = note: this error originates in the macro `max` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0433]: failed to resolve: use of undeclared type `Ordering`
  --> /home/hbina085/git/rustlang/tests/assembly/rust-abi-arg-attr.rs:25:13
   |
25 |             Ordering::Less | Ordering::Equal => $b,
   |             ^^^^^^^^ use of undeclared type `Ordering`
...
48 |     max!(a, b)
   |     ---------- in this macro invocation
   |
   = note: this error originates in the macro `max` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0433]: failed to resolve: use of undeclared type `Ordering`
  --> /home/hbina085/git/rustlang/tests/assembly/rust-abi-arg-attr.rs:25:30
   |
25 |             Ordering::Less | Ordering::Equal => $b,
   |                              ^^^^^^^^ use of undeclared type `Ordering`
...
48 |     max!(a, b)
   |     ---------- in this macro invocation
   |
   = note: this error originates in the macro `max` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0433]: failed to resolve: use of undeclared type `Ordering`
  --> /home/hbina085/git/rustlang/tests/assembly/rust-abi-arg-attr.rs:26:13
   |
26 |             Ordering::Greater => $a,
   |             ^^^^^^^^ use of undeclared type `Ordering`
...
48 |     max!(a, b)
   |     ---------- in this macro invocation
   |
   = note: this error originates in the macro `max` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0433]: failed to resolve: use of undeclared type `Ordering`
  --> /home/hbina085/git/rustlang/tests/assembly/rust-abi-arg-attr.rs:25:13
   |
25 |             Ordering::Less | Ordering::Equal => $b,
   |             ^^^^^^^^ use of undeclared type `Ordering`
...
68 |     max!(a, b)
   |     ---------- in this macro invocation
   |
   = note: this error originates in the macro `max` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0433]: failed to resolve: use of undeclared type `Ordering`
  --> /home/hbina085/git/rustlang/tests/assembly/rust-abi-arg-attr.rs:25:30
   |
25 |             Ordering::Less | Ordering::Equal => $b,
   |                              ^^^^^^^^ use of undeclared type `Ordering`
...
68 |     max!(a, b)
   |     ---------- in this macro invocation
   |
   = note: this error originates in the macro `max` (in Nightly builds, run with -Z macro-backtrace for more info)

error[E0433]: failed to resolve: use of undeclared type `Ordering`
  --> /home/hbina085/git/rustlang/tests/assembly/rust-abi-arg-attr.rs:26:13
   |
26 |             Ordering::Greater => $a,
   |             ^^^^^^^^ use of undeclared type `Ordering`
...
68 |     max!(a, b)
   |     ---------- in this macro invocation
   |
   = note: this error originates in the macro `max` (in Nightly builds, run with -Z macro-backtrace for more info)

error: aborting due to 8 previous errors; 1 warning emitted

It doesn't look like minicore have Ordering or three_way_compare, should i implement those?

diff --git a/tests/assembly/rust-abi-arg-attr.rs b/tests/assembly/rust-abi-arg-attr.rs
index 5b5eeb29f0f..5b241cb84dd 100644
--- a/tests/assembly/rust-abi-arg-attr.rs
+++ b/tests/assembly/rust-abi-arg-attr.rs
@@ -1,3 +1,4 @@
+//@ add-core-stubs
 //@ assembly-output: emit-asm
 //@ revisions: riscv64 riscv64-zbb loongarch64
 //@ compile-flags: -C opt-level=3
@@ -14,46 +15,8 @@
 #![no_std]
 #![no_core]
 
-// FIXME: Migrate these code after PR #130693 is landed.
-// vvvvv core
-
-#[lang = "sized"]
-trait Sized {}
-
-#[lang = "copy"]
-trait Copy {}
-
-impl Copy for i8 {}
-impl Copy for u32 {}
-impl Copy for i32 {}
-
-#[lang = "neg"]
-trait Neg {
-    type Output;
-
-    fn neg(self) -> Self::Output;
-}
-
-impl Neg for i8 {
-    type Output = i8;
-
-    fn neg(self) -> Self::Output {
-        -self
-    }
-}
-
-#[lang = "Ordering"]
-#[repr(i8)]
-enum Ordering {
-    Less = -1,
-    Equal = 0,
-    Greater = 1,
-}
-
-#[rustc_intrinsic]
-fn three_way_compare<T: Copy>(lhs: T, rhs: T) -> Ordering;
-
-// ^^^^^ core
+extern crate minicore;
+use minicore::*;
 
 // Reimplementation of function `{integer}::max`.
 macro_rules! max {

[hbina]

This is the list of files if anyone is interested

hbina085@DESKTOP-PGERPVO ~/g/rustlang (master) [127]> rg --context 10000000 '\#\[rustc_intrinsic\]' /home/hbina085/git/rustlang/tests/**.rs | rg '\#!\[no_core\]'                                    (base) 
/home/hbina085/git/rustlang/tests/ui/traits/const-traits/auxiliary/minicore.rs-#![no_core]
/home/hbina085/git/rustlang/tests/ui/target-feature/feature-hierarchy.rs-#![no_core]
/home/hbina085/git/rustlang/tests/ui/target-feature/no-llvm-leaks.rs-#![no_core]
/home/hbina085/git/rustlang/tests/ui/repr/16-bit-repr-c-enum.rs-#![no_core]
/home/hbina085/git/rustlang/tests/rustdoc/safe-intrinsic.rs-#![no_core]
/home/hbina085/git/rustlang/tests/run-make/avr-rjmp-offset/avr-rjmp-offsets.rs-//! This test case is a `#![no_core]`-version of the MVCE presented in #129301.
/home/hbina085/git/rustlang/tests/run-make/avr-rjmp-offset/avr-rjmp-offsets.rs-#![no_core]
/home/hbina085/git/rustlang/tests/run-make/atomic-lock-free/atomic_lock_free.rs-#![no_core]
/home/hbina085/git/rustlang/tests/assembly/simd-intrinsic-mask-load.rs-#![no_core]
/home/hbina085/git/rustlang/tests/codegen/emscripten-catch-unwind-js-eh.rs-#![no_core]
/home/hbina085/git/rustlang/tests/codegen/avr/avr-func-addrspace.rs-#![no_core]
/home/hbina085/git/rustlang/tests/auxiliary/minicore.rs-#![no_core]
/home/hbina085/git/rustlang/tests/assembly/simd-intrinsic-mask-reduce.rs-#![no_core]
/home/hbina085/git/rustlang/tests/assembly/simd-intrinsic-scatter.rs-#![no_core]
/home/hbina085/git/rustlang/tests/assembly/simd-bitmask.rs-#![no_core]
/home/hbina085/git/rustlang/tests/codegen/intrinsics/nontemporal.rs-#![no_core]
/home/hbina085/git/rustlang/tests/assembly/simd-intrinsic-select.rs-#![no_core]
/home/hbina085/git/rustlang/tests/assembly/simd-intrinsic-gather.rs-#![no_core]
/home/hbina085/git/rustlang/tests/assembly/simd-intrinsic-mask-store.rs-#![no_core]
/home/hbina085/git/rustlang/tests/codegen/emscripten-catch-unwind-wasm-eh.rs-#![no_core]