As Windows 10 requires certain features like CMPXCHG16B and a few oth…

…ers and Rust plans to set Windows 10 as the minimum supported OS for target x86_64-pc-windows-msvc, I have added the cmpxchg16b and sse3 feature (as CPUs that meet the Windows 10 64-bit requirement also support SSE3. See https://walbourn.github.io/directxmath-sse3-and-ssse3/ )

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

@@ -3,6 +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.plt_by_default = false;
     base.max_atomic_width = Some(64);
     base.supported_sanitizers = SanitizerSet::ADDRESS;