Rollup merge of #145099 - heiher:loong-32s, r=folkertdev

rustc_target: Add the `32s` target feature for LoongArch

LLVM: https://github.com/llvm/llvm-project/pull/139695

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,
         (