std: Remove unneeded gates from std_detect

We have a handful of `#[unstable]` gates that aren't even being used,
because all that matters is the re-export in `std`. For example, the
RISC-V macro appears unstable, but has actually been stable since 1.78
<https://doc.rust-lang.org/1.78.0/std/arch/macro.is_riscv_feature_detected.html>.

Author: tgross35

library/std_detect/src/detect/arch/mod.rs

@@ -22,40 +22,40 @@ mod s390x;
 
 cfg_select! {
     any(target_arch = "x86", target_arch = "x86_64") => {
-        #[stable(feature = "simd_x86", since = "1.27.0")]
-        pub use x86::*;
+        pub use x86::__is_feature_detected;
+        pub(crate) use x86::Feature;
     }
     target_arch = "arm" => {
-        #[unstable(feature = "stdarch_arm_feature_detection", issue = "111190")]
-        pub use arm::*;
+        pub use arm::__is_feature_detected;
+        pub(crate) use arm::Feature;
     }
     any(target_arch = "aarch64", target_arch = "arm64ec") => {
-        #[stable(feature = "simd_aarch64", since = "1.60.0")]
-        pub use aarch64::*;
+        pub use aarch64::__is_feature_detected;
+        pub(crate) use aarch64::Feature;
     }
     any(target_arch = "riscv32", target_arch = "riscv64") => {
-        #[unstable(feature = "stdarch_riscv_feature_detection", issue = "111192")]
-        pub use riscv::*;
+        pub use riscv::__is_feature_detected;
+        pub(crate) use riscv::Feature;
     }
     any(target_arch = "powerpc", target_arch = "powerpc64") => {
-        #[unstable(feature = "stdarch_powerpc_feature_detection", issue = "111191")]
-        pub use powerpc::*;
+        pub use powerpc::__is_feature_detected;
+        pub(crate) use powerpc::Feature;
     }
     target_arch = "mips" => {
-        #[unstable(feature = "stdarch_mips_feature_detection", issue = "111188")]
-        pub use mips::*;
+        pub use mips::__is_feature_detected;
+        pub(crate) use mips::Feature;
     }
     target_arch = "mips64" => {
-        #[unstable(feature = "stdarch_mips_feature_detection", issue = "111188")]
-        pub use mips64::*;
+        pub use mips64::__is_feature_detected;
+        pub(crate) use mips64::Feature;
     }
     any(target_arch = "loongarch32", target_arch = "loongarch64") => {
-        #[stable(feature = "stdarch_loongarch_feature", since = "1.89.0")]
-        pub use loongarch::*;
+        pub use loongarch::__is_feature_detected;
+        pub(crate) use loongarch::Feature;
     }
     target_arch = "s390x" => {
-        #[stable(feature = "stdarch_s390x_feature_detection", since = "1.93.0")]
-        pub use s390x::*;
+        pub use s390x::__is_feature_detected;
+        pub(crate) use s390x::Feature;
     }
     _ => {
         // Unimplemented architecture:
@@ -64,7 +64,6 @@ cfg_select! {
             Null,
         }
         #[doc(hidden)]
-        #[unstable(feature = "stdarch_internal", issue = "none")]
         pub mod __is_feature_detected {}
 
         impl Feature {

library/std_detect/src/detect/macros.rs

@@ -181,7 +181,6 @@ macro_rules! features {
         /// to change.
         #[doc(hidden)]
         #[cfg($cfg)]
-        #[unstable(feature = "stdarch_internal", issue = "none")]
         pub mod __is_feature_detected {
             $(
 

library/std_detect/src/detect/mod.rs

@@ -24,7 +24,6 @@ mod arch;
 
 // This module needs to be public because the `is_{arch}_feature_detected!`
 // macros expand calls to items within it in user crates.
-#[doc(hidden)]
 #[unstable(feature = "stdarch_internal", issue = "none")]
 pub use self::arch::__is_feature_detected;
 pub(crate) use self::arch::Feature;