Auto merge of #144542 - sayantn:stabilize-sse4a-tbm, r=Amanieu,traviscross

Stabilize `sse4a` and `tbm` target features

This PR stabilizes the feature flag `sse4a_target_feature` and `tbm_target_feature` (tracking issue rust-lang/rust#44839).

# Public API
The 2 `x86` target features `sse4a` and `tbm`

Also, these were added in LLVM2.6 and LLVM3.4-rc1, respectively, and as the minimum LLVM required for rustc is LLVM19, we are safe in that front too!

As all of the required tasks have been done (adding the target features to rustc, implementing their runtime detection in std_detect and implementing the associated intrinsics in core_arch), these target features can be stabilized now. The intrinsics were stabilized *long* ago, in 1.27.0

Reference PR:

- https://github.com/rust-lang/reference/pull/1949

cc `@rust-lang/lang`

`@rustbot` label I-lang-nominated
r? lang

3 files changed, 6 insertions, 4 deletions

diff --git a/compiler/rustc_feature/src/accepted.rs b/compiler/rustc_feature/src/accepted.rs
index 83be3241b12..9fe55216f93 100644
--- a/compiler/rustc_feature/src/accepted.rs
+++ b/compiler/rustc_feature/src/accepted.rs
@@ -396,6 +396,8 @@ declare_features! (
     (accepted, slice_patterns, "1.42.0", Some(62254)),
     /// Allows use of `&foo[a..b]` as a slicing syntax.
     (accepted, slicing_syntax, "1.0.0", None),
+    /// Allows use of `sse4a` target feature.
+    (accepted, sse4a_target_feature, "CURRENT_RUSTC_VERSION", Some(44839)),
     /// Allows elision of `'static` lifetimes in `static`s and `const`s.
     (accepted, static_in_const, "1.17.0", Some(35897)),
     /// Allows the definition recursive static items.
@@ -408,6 +410,8 @@ declare_features! (
     (accepted, target_feature, "1.27.0", None),
     /// Allows the use of `#[target_feature]` on safe functions.
     (accepted, target_feature_11, "1.86.0", Some(69098)),
+    /// Allows use of `tbm` target feature.
+    (accepted, tbm_target_feature, "CURRENT_RUSTC_VERSION", Some(44839)),
     /// Allows `fn main()` with return types which implements `Termination` (RFC 1937).
     (accepted, termination_trait, "1.26.0", Some(43301)),
     /// Allows `#[test]` functions where the return type implements `Termination` (RFC 1937).
diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs
index acc21f6c6d2..87ecc7b41e2 100644
--- a/compiler/rustc_feature/src/unstable.rs
+++ b/compiler/rustc_feature/src/unstable.rs
@@ -334,8 +334,6 @@ declare_features! (
     (unstable, rtm_target_feature, "1.35.0", Some(44839)),
     (unstable, s390x_target_feature, "1.82.0", Some(44839)),
     (unstable, sparc_target_feature, "1.84.0", Some(132783)),
-    (unstable, sse4a_target_feature, "1.27.0", Some(44839)),
-    (unstable, tbm_target_feature, "1.27.0", Some(44839)),
     (unstable, wasm_target_feature, "1.30.0", Some(44839)),
     (unstable, x87_target_feature, "1.85.0", Some(44839)),
     // !!!!    !!!!    !!!!    !!!!   !!!!    !!!!    !!!!    !!!!    !!!!    !!!!    !!!!
diff --git a/compiler/rustc_target/src/target_features.rs b/compiler/rustc_target/src/target_features.rs
index 4b450804f3b..507e938d5cc 100644
--- a/compiler/rustc_target/src/target_features.rs
+++ b/compiler/rustc_target/src/target_features.rs
@@ -475,9 +475,9 @@ static X86_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     ("sse3", Stable, &["sse2"]),
     ("sse4.1", Stable, &["ssse3"]),
     ("sse4.2", Stable, &["sse4.1"]),
-    ("sse4a", Unstable(sym::sse4a_target_feature), &["sse3"]),
+    ("sse4a", Stable, &["sse3"]),
     ("ssse3", Stable, &["sse3"]),
-    ("tbm", Unstable(sym::tbm_target_feature), &[]),
+    ("tbm", Stable, &[]),
     ("vaes", Stable, &["avx2", "aes"]),
     ("vpclmulqdq", Stable, &["avx", "pclmulqdq"]),
     ("widekl", Stable, &["kl"]),