Ignore backtrace test on Windows

Temporarily ignoring Winch's trap test on Windows while
support for unwind information is added.

tests/all/winch.rs

@@ -124,7 +124,9 @@ fn wasm_to_native() -> Result<()> {
 
 #[test]
 #[cfg_attr(miri, ignore)]
+#[cfg_attr(windows, ignore)]
 // NB
+//
 // This and the following test(`native_to_wasm_trap` and `wasm_to_native_trap`),
 // are mostly smoke tests to ensure Winch's trampolines are compliant with fast
 // stack walking. The ideal state is one in which we should not have to worry
@@ -133,6 +135,9 @@ fn wasm_to_native() -> Result<()> {
 // code generated by Winch and Cranelift is compliant. One way to achieve this
 // could be to share the implementation of trampolines between Cranelift and
 // Winch.
+//
+// FIXME The following two tests are also temporarily ignored on Windows, since
+// we are not emitting the require unwind information yet.
 fn native_to_wasm_trap() -> Result<()> {
     let mut c = Config::new();
     c.strategy(Strategy::Winch);
@@ -159,6 +164,7 @@ fn native_to_wasm_trap() -> Result<()> {
 
 #[test]
 #[cfg_attr(miri, ignore)]
+#[cfg_attr(windows, ignore)]
 fn wasm_to_native_trap() -> Result<()> {
     let mut c = Config::new();
     c.strategy(Strategy::Winch);