Initial work to build for Windows ARM64 (#4990)

* Make wasmtime build for windows-aarch64

* Add check for win arm64 build.

* Fix checks for winarm64 key in workflows.

* Add target in windows arm64 build.

* Add tracking issue for Windows ARM64 trap handling

crates/jit/src/unwind.rs

@@ -5,6 +5,9 @@ cfg_if::cfg_if! {
     } 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::*;