Partially stabilize LoongArch target features

Author: heiher

compiler/rustc_target/src/target_features.rs

@@ -581,11 +581,11 @@ const LOONGARCH_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
     ("d", Unstable(sym::loongarch_target_feature), &["f"]),
     ("f", Unstable(sym::loongarch_target_feature), &[]),
-    ("frecipe", Unstable(sym::loongarch_target_feature), &[]),
-    ("lasx", Unstable(sym::loongarch_target_feature), &["lsx"]),
-    ("lbt", Unstable(sym::loongarch_target_feature), &[]),
-    ("lsx", Unstable(sym::loongarch_target_feature), &["d"]),
-    ("lvz", Unstable(sym::loongarch_target_feature), &[]),
+    ("frecipe", Stable, &[]),
+    ("lasx", Stable, &["lsx"]),
+    ("lbt", Stable, &[]),
+    ("lsx", Stable, &["d"]),
+    ("lvz", Stable, &[]),
     ("relax", Unstable(sym::loongarch_target_feature), &[]),
     ("ual", Unstable(sym::loongarch_target_feature), &[]),
     // tidy-alphabetical-end