Enable outline-atomics by default on AArch64 Windows platforms

Windows has a similar flag `/forceInterlockedFunctions`, which uses
names such as `_InterlockedAdd64_rel`.

Author: tgross35

compiler/rustc_target/src/spec/targets/aarch64_pc_windows_gnullvm.rs

@@ -3,7 +3,7 @@ use crate::spec::{FramePointer, Target, TargetMetadata, base};
 pub(crate) fn target() -> Target {
     let mut base = base::windows_gnullvm::opts();
     base.max_atomic_width = Some(128);
-    base.features = "+v8a,+neon,+fp-armv8".into();
+    base.features = "+v8a,+neon,+fp-armv8,+outline-atomics".into();
     base.linker = Some("aarch64-w64-mingw32-clang".into());
 
     // Microsoft recommends enabling frame pointers on Arm64 Windows.

compiler/rustc_target/src/spec/targets/aarch64_pc_windows_msvc.rs

@@ -3,7 +3,7 @@ use crate::spec::{FramePointer, Target, TargetMetadata, base};
 pub(crate) fn target() -> Target {
     let mut base = base::windows_msvc::opts();
     base.max_atomic_width = Some(128);
-    base.features = "+v8a,+neon,+fp-armv8".into();
+    base.features = "+v8a,+neon,+fp-armv8,+outline-atomics".into();
 
     // Microsoft recommends enabling frame pointers on Arm64 Windows.
     // From https://learn.microsoft.com/en-us/cpp/build/arm64-windows-abi-conventions?view=msvc-170#integer-registers