Fix fatal error for external with @as

Author: cknitt

compiler/frontend/ast_external_process.ml

@@ -1009,7 +1009,7 @@ let handle_attributes (loc : Bs_loc.t) (type_annotation : Parsetree.core_type)
       check_return_wrapper loc external_desc.return_wrapper result_type
     in
     let fn_type = Ast_helper.Typ.arrows ~loc args result_type in
-    ( build_uncurried_type ~arity:(List.length args) fn_type,
+    ( fn_type,
       External_ffi_types.ffi_bs arg_type_specs return_wrapper ffi,
       unused_attrs,
       relative )

tests/tests/src/AsInUncurriedExternals.mjs

@@ -19,9 +19,12 @@ function shouldNotFail(objectMode, name) {
   return 3;
 }
 
+let constantValue = somescope.somefn({foo:true});
+
 export {
   mo,
   options,
   shouldNotFail,
+  constantValue,
 }
-/* No side effect */
+/* constantValue Not a pure module */

tests/tests/src/AsInUncurriedExternals.res

@@ -13,3 +13,8 @@ let mo = makeOptions
 let options = mo(~name="foo", ())
 
 let shouldNotFail: (~objectMode: _, ~name: string) => int = (~objectMode, ~name) => 3
+
+@scope("somescope")
+external constantArgOnly: @as(json`{foo:true}`) _ => string = "somefn"
+
+let constantValue = constantArgOnly