add autodiff batching fix

Author: ZuseZ4

compiler/rustc_codegen_llvm/src/builder/autodiff.rs

@@ -125,11 +125,11 @@ fn match_args_from_caller_to_enzyme<'ll>(
                 // int2 >= int1, which means the shadow vector is large enough to store the gradient.
                 assert_eq!(cx.type_kind(next_outer_ty), TypeKind::Integer);
 
-                for _ in 0..width {
-                    let next_outer_arg2 = outer_args[outer_pos + 2];
+                for i in 0..(width as usize) {
+                    let next_outer_arg2 = outer_args[outer_pos + 2 * (i + 1)];
                     let next_outer_ty2 = cx.val_ty(next_outer_arg2);
                     assert_eq!(cx.type_kind(next_outer_ty2), TypeKind::Pointer);
-                    let next_outer_arg3 = outer_args[outer_pos + 3];
+                    let next_outer_arg3 = outer_args[outer_pos + 2 * (i + 1) + 1];
                     let next_outer_ty3 = cx.val_ty(next_outer_arg3);
                     assert_eq!(cx.type_kind(next_outer_ty3), TypeKind::Integer);
                     args.push(next_outer_arg2);