rustc_target: Add the 32s target feature for LoongArch

Author: heiher

compiler/rustc_codegen_llvm/src/llvm_util.rs

@@ -277,6 +277,7 @@ pub(crate) fn to_llvm_features<'a>(sess: &Session, s: &'a str) -> Option<LLVMFea
         {
             None
         }
+        ("loongarch32" | "loongarch64", "32s") if get_version().0 < 21 => None,
         // Filter out features that are not supported by the current LLVM version
         ("riscv32" | "riscv64", "zacas") if get_version().0 < 20 => None,
         (

compiler/rustc_target/src/target_features.rs

@@ -763,6 +763,7 @@ static CSKY_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
 
 static LOONGARCH_FEATURES: &[(&str, Stability, ImpliedFeatures)] = &[
     // tidy-alphabetical-start
+    ("32s", Unstable(sym::loongarch_target_feature), &[]),
     ("d", Stable, &["f"]),
     ("div32", Unstable(sym::loongarch_target_feature), &[]),
     ("f", Stable, &[]),

tests/ui/check-cfg/target_feature.stderr

@@ -6,6 +6,7 @@ LL |     cfg!(target_feature = "_UNEXPECTED_VALUE");
    |
    = note: expected values for `target_feature` are: `10e60`
 `2e3`
+`32s`
 `3e3r1`
 `3e3r2`
 `3e3r3`