Consolidate module definition in wasmtime-jit (#5000)

Minor thing I noticed from #4990 but I stylistically prefer to keep the
`mod foo;` definitions canonicalized to one location to emphasize how
multiple targets can use the same definition.

crates/jit/src/unwind.rs

@@ -1,13 +1,10 @@
 cfg_if::cfg_if! {
-    if #[cfg(all(windows, target_arch = "x86_64"))] {
+    if #[cfg(all(windows, any(target_arch = "x86_64", target_arch = "aarch64")))] {
         mod winx64;
         pub use self::winx64::*;
     } else if #[cfg(all(windows, target_arch = "x86"))] {
         mod winx32;
         pub use self::winx32::*;
-    } else if #[cfg(all(windows, target_arch = "aarch64"))] {
-        mod winx64;
-        pub use self::winx64::*;
     } else if #[cfg(unix)] {
         mod systemv;
         pub use self::systemv::*;