Fix issue where partial application ... can use Curry at runtime.

See example:
https://rescript-lang.org/try?version=v11.1.2&code=ALCuDsGNQJxhLApgEwFCoDaIC4AICGyyuAvLgB6kB8uAFAJ4A0uAXgJTUW4DUu9PrdFjwAzUrlCcA3qly5huMWULJaoNrMW0AjMwB0BjQF9UQA

Author: cristianoc

CHANGELOG.md

@@ -42,6 +42,7 @@
 - Reactivate unused attribute check for `@int`. https://github.com/rescript-lang/rescript-compiler/pull/6802
 - Fix Deno compatibility issues on Windows. https://github.com/rescript-lang/rescript-compiler/pull/6850
 - Fix issue with infinite loops with type errors on recursive types. https://github.com/rescript-lang/rescript-compiler/pull/6867
+- Fix issue where using partial application `...` can generate code that uses `Curry` at runtime. https://github.com/rescript-lang/rescript-compiler/pull/6872
 
 #### :house: Internal
 

jscomp/ml/translcore.ml

@@ -1099,16 +1099,16 @@ and transl_apply ?(inlined = Default_inline) ?(uncurried_partial_application=Non
         let id_arg = Ident.create "none" in
         none_ids := id_arg :: !none_ids;
         Some (Lvar id_arg)) in
-    let extra_ids = ref [] in
-    extra_ids := Ident.create "extra" :: !extra_ids;
     let extra_ids = Array.init extra_arity (fun _ -> Ident.create "extra") |> Array.to_list in
     let extra_args = Ext_list.map extra_ids (fun id -> Lvar id) in
     let ap_args = args @ extra_args in
-    let l0 = Lapply { ap_func = lam; ap_args; ap_inlined = inlined; ap_loc = loc } in
+    let lam_opaque = Lprim (Popaque, [lam], loc) in
+    let l0 = Lapply { ap_func = lam_opaque; ap_args; ap_inlined = inlined; ap_loc = loc } in
+    let l1 = Lprim (Puncurried_apply, [l0], loc) in
     Lfunction
       {
         params = List.rev_append !none_ids extra_ids ;
-        body = l0;
+        body = l1;
         attr = default_function_attribute;
         loc;
       }

jscomp/test/PartialApplicationNoRuntimeCurry.js

@@ -0,0 +1,8 @@
+@@uncurried
+
+let add = x => (y, z) => x + y + z
+
+let f = u => {
+  let f = add(u)
+  f(1, ...)
+}