Whitelist stable target-features in typeck

Author: gnzlbg

src/librustc_typeck/collect.rs

@@ -2362,14 +2362,16 @@ fn from_target_feature(
                 Some(sym::mips_target_feature) => rust_features.mips_target_feature,
                 Some(sym::avx512_target_feature) => rust_features.avx512_target_feature,
                 Some(sym::mmx_target_feature) => rust_features.mmx_target_feature,
-                Some(sym::sse4a_target_feature) => rust_features.sse4a_target_feature,
-                Some(sym::tbm_target_feature) => rust_features.tbm_target_feature,
                 Some(sym::wasm_target_feature) => rust_features.wasm_target_feature,
                 Some(sym::cmpxchg16b_target_feature) => rust_features.cmpxchg16b_target_feature,
-                Some(sym::adx_target_feature) => rust_features.adx_target_feature,
                 Some(sym::movbe_target_feature) => rust_features.movbe_target_feature,
                 Some(sym::rtm_target_feature) => rust_features.rtm_target_feature,
                 Some(sym::f16c_target_feature) => rust_features.f16c_target_feature,
+                // These are stable:
+                | Some(sym::sse4a_target_feature)
+                | Some(sym::tbm_target_feature)
+                | Some(sym::adx_target_feature)
+                    => true,
                 Some(name) => bug!("unknown target feature gate {}", name),
                 None => true,
             };