Add test to make sure fixed length works

Signed-off-by: James Sturtevant <jsturtevant@gmail.com>

Author: jsturtevant

src/hyperlight_host/tests/wit_test.rs

@@ -155,6 +155,9 @@ impl test::wit::Roundtrip for Host {
     ) -> test::wit::roundtrip::Testenum {
         x
     }
+    fn roundtrip_fix_list(&mut self, x: Vec<u8>) -> Vec<u8> {
+        x
+    }
 
     fn roundtrip_no_result(&mut self, _x: u32) {}
 }
@@ -331,6 +334,7 @@ mod wit_test {
     make_test! { roundtrip_flags_large, in arb_largeflags() }
     make_test! { roundtrip_variant,     in arb_testvariant() }
     make_test! { roundtrip_enum,        in arb_testenum() }
+    make_test! { roundtrip_fix_list,    : Vec<u8> }
 
     #[test]
     fn test_simple_func() {

src/tests/rust_guests/witguest/guest.wit

@@ -26,6 +26,7 @@ interface roundtrip {
   roundtrip-option: func(x: option<string>) -> option<string>;
   roundtrip-result: func(x: result<char, string>) -> result<char, string>;
   roundtrip-no-result: func(x: u32);
+  roundtrip-fix-list: func(x: list<u8, 4>) -> list<u8, 4>;
 
   record testrecord {
     contents: string,

src/tests/rust_guests/witguest/src/main.rs

@@ -113,6 +113,9 @@ impl test::wit::Roundtrip for Guest {
     ) -> test::wit::roundtrip::Testenum {
         (Host {}).roundtrip_enum(x)
     }
+    fn roundtrip_fix_list(&mut self, x: Vec<u8>) -> Vec<u8> {
+        (Host {}).roundtrip_fix_list(x)
+    }
     fn roundtrip_no_result(&mut self, x: u32) {
         (Host {}).roundtrip_no_result(x)
     }