Fix FixedSizeList type silently losing size and Map todo panic

FixedSizeList was being converted to a regular List, discarding the size
parameter. Now correctly maps to DefinedType::FixedSizeList preserving
both the element type and size.

Also replaced the todo!() panic for ComponentDefinedType::Map with a
proper error, since encountering Map types at runtime should not crash.

Author: sumleo

crates/wac-types/src/package.rs

@@ -754,12 +754,12 @@ impl<'a> TypeConverter<'a> {
                 let option = ty.map(|ty| self.component_val_type(ty)).transpose()?;
                 ValueType::Defined(self.types.add_defined_type(DefinedType::Future(option)))
             }
-            wasm::ComponentDefinedType::FixedSizeList(ty, _) => {
+            wasm::ComponentDefinedType::FixedSizeList(ty, size) => {
                 let ty = self.component_val_type(*ty)?;
-                ValueType::Defined(self.types.add_defined_type(DefinedType::List(ty)))
+                ValueType::Defined(self.types.add_defined_type(DefinedType::FixedSizeList(ty, *size)))
             }
             wasmparser::component_types::ComponentDefinedType::Map(_, _) => {
-                todo!("wasmparser::component_types::ComponentDefinedType::Map");
+                bail!("ComponentDefinedType::Map is not yet supported");
             }
         };