Provide a module for direct inclusion by libstd

Author: gnzlbg

crates/std_detect/Cargo.toml

@@ -23,13 +23,8 @@ is-it-maintained-open-issues = { repository = "rust-lang-nursery/stdsimd" }
 maintenance = { status = "experimental" }
 
 [dependencies]
-libc = "0.2"
+libc = { version = "0.2", default-features = false }
 cfg-if = { version = "^0.1.6", default-features = false }
-rustc-std-workspace-core = { version = "1.0.0", optional = true }
-
-[features]
-default = []
-rustc-dep-of-std = [ 'libc/rustc-dep-of-std', 'rustc-std-workspace-core' ]
 
 [dev-dependencies]
 core_arch = { version = "0.1.3", path = "../core_arch" }

crates/std_detect/src/detect/mod.rs

@@ -68,7 +68,7 @@ cfg_if! {
         // On x86/x86_64 no OS specific functionality is required.
         #[path = "os/x86.rs"]
         mod os;
-    } else if #[cfg(target_os = "linux")] {
+    } else if #[cfg(all(target_os = "linux", feature = "use_std"))] {
         #[path = "os/linux/mod.rs"]
         mod os;
     } else if #[cfg(target_os = "freebsd")] {

crates/std_detect/src/lib.rs

@@ -11,6 +11,7 @@
 //! * `powerpc`: [`is_powerpc_feature_detected`]
 //! * `powerpc64`: [`is_powerpc64_feature_detected`]
 
+#![unstable(feature = "stdsimd", issue = "27731")]
 #![feature(const_fn, integer_atomics, staged_api, stdsimd)]
 #![feature(doc_cfg, allow_internal_unstable)]
 #![cfg_attr(feature = "cargo-clippy", allow(clippy::shadow_reuse))]
@@ -21,7 +22,6 @@
 #![cfg_attr(target_os = "linux", feature(linkage))]
 #![cfg_attr(all(target_os = "freebsd", target_arch = "aarch64"), feature(asm))]
 #![no_std]
-#![unstable(feature = "stdsimd", issue = "27731")]
 
 #[cfg(test)]
 #[macro_use(println)]

crates/std_detect/src/mod.rs

@@ -0,0 +1,5 @@
+//! `std_detect`
+
+#[doc(hidden)] // unstable implementation detail
+#[unstable(feature = "stdsimd", issue = "27731")]
+pub mod detect;