LLVM: LLVM-20.0 removes MMX types

See llvm/llvm-project#98505

Author: maurer

compiler/rustc_llvm/llvm-wrapper/RustWrapper.cpp

@@ -1419,8 +1419,10 @@ extern "C" LLVMTypeKind LLVMRustGetTypeKind(LLVMTypeRef Ty) {
     return LLVMPointerTypeKind;
   case Type::FixedVectorTyID:
     return LLVMVectorTypeKind;
+#if LLVM_VERSION_LT(20, 0)
   case Type::X86_MMXTyID:
     return LLVMX86_MMXTypeKind;
+#endif
   case Type::TokenTyID:
     return LLVMTokenTypeKind;
   case Type::ScalableVectorTyID: