Update x86_64_pc_windows_msvc.rs

Fixed a bug where adding CMPXCHG16B would fail due to different names in Rustc and LLVM

Author: CKingX

compiler/rustc_target/src/spec/targets/x86_64_pc_windows_msvc.rs

@@ -3,7 +3,7 @@ use crate::spec::{base, SanitizerSet, Target};
 pub fn target() -> Target {
     let mut base = base::windows_msvc::opts();
     base.cpu = "x86-64".into();
-    base.features = "+cmpxchg16b,+sse3".into();
+    base.features = "+cx16,+sse3".into();
     base.plt_by_default = false;
     base.max_atomic_width = Some(64);
     base.supported_sanitizers = SanitizerSet::ADDRESS;