Fix std_detect not being an unstable crate

More fallout from #1486

crates/core_arch/src/lib.rs

@@ -35,7 +35,7 @@
     inline_const,
     generic_arg_infer
 )]
-#![cfg_attr(test, feature(test, abi_vectorcall))]
+#![cfg_attr(test, feature(test, abi_vectorcall, stdarch_internal))]
 #![deny(clippy::missing_inline_in_public_items)]
 #![allow(
     clippy::identity_op,

crates/std_detect/src/lib.rs

@@ -13,7 +13,7 @@
 //! * `powerpc64`: [`is_powerpc64_feature_detected`]
 //! * `loongarch`: [`is_loongarch_feature_detected`]
 
-#![stable(feature = "stdsimd", since = "1.27.0")]
+#![unstable(feature = "stdarch_internal", issue = "none")]
 #![feature(staged_api, doc_cfg, allow_internal_unstable)]
 #![deny(rust_2018_idioms)]
 #![allow(clippy::shadow_reuse)]
@@ -23,7 +23,7 @@
 // Temporary hack: needed to build against toolchains from before the mass feature renaming.
 // Remove this as soon as the stdarch submodule is updated on nightly.
 #![allow(stable_features)]
-#![feature(stdsimd)]
+#![cfg_attr(not(feature = "rustc-dep-of-std"), feature(stdsimd))]
 #![cfg_attr(
     all(
         any(target_arch = "x86", target_arch = "x86_64"),
@@ -42,5 +42,5 @@ extern crate std;
 extern crate alloc;
 
 #[doc(hidden)]
-#[stable(feature = "stdsimd", since = "1.27.0")]
+#[unstable(feature = "stdarch_internal", issue = "none")]
 pub mod detect;

crates/std_detect/tests/macro_trailing_commas.rs

@@ -1,3 +1,15 @@
+#![allow(internal_features)]
+#![cfg_attr(
+    any(
+        target_arch = "arm",
+        target_arch = "aarch64",
+        target_arch = "x86",
+        target_arch = "x86_64",
+        target_arch = "powerpc",
+        target_arch = "powerpc64"
+    ),
+    feature(stdarch_internal)
+)]
 #![cfg_attr(target_arch = "arm", feature(stdarch_arm_feature_detection))]
 #![cfg_attr(target_arch = "powerpc", feature(stdarch_powerpc_feature_detection))]
 #![cfg_attr(target_arch = "powerpc64", feature(stdarch_powerpc_feature_detection))]

crates/std_detect/tests/x86-specific.rs

@@ -1,4 +1,6 @@
 #![cfg(any(target_arch = "x86", target_arch = "x86_64"))]
+#![allow(internal_features)]
+#![feature(stdarch_internal)]
 
 extern crate cupid;
 #[macro_use]

examples/connect5.rs

@@ -28,9 +28,10 @@
 //! You should see a game self-playing. In the end of the game, it shows the average time for
 //! each move.
 
+#![allow(internal_features)]
 #![feature(avx512_target_feature)]
-#![cfg_attr(target_arch = "x86", feature(stdarch_x86_avx512))]
-#![cfg_attr(target_arch = "x86_64", feature(stdarch_x86_avx512))]
+#![cfg_attr(target_arch = "x86", feature(stdarch_x86_avx512, stdarch_internal))]
+#![cfg_attr(target_arch = "x86_64", feature(stdarch_x86_avx512, stdarch_internal))]
 #![feature(stmt_expr_attributes)]
 
 use rand::seq::SliceRandom;

examples/hex.rs

@@ -12,8 +12,13 @@
 //!
 //! and you should see `746573740a` get printed out.
 
+#![allow(internal_features)]
 #![feature(wasm_target_feature)]
 #![cfg_attr(test, feature(test))]
+#![cfg_attr(
+    any(target_arch = "x86", target_arch = "x86_64"),
+    feature(stdarch_internal)
+)]
 #![allow(
     clippy::unwrap_used,
     clippy::print_stdout,