atpos_o-for-MVMIntArray.diff

diff --git a/src/core/interp.c b/src/core/interp.c
index 069dd55..e2688e1 100644
--- a/src/core/interp.c
+++ b/src/core/interp.c
@@ -1908,10 +1908,42 @@ void MVM_interp_run(MVMThreadContext *tc, void (*initial_invoke)(MVMThreadContex
                         break;
                     }
                     case MVM_OP_atpos_o: {
-                        MVMObject *obj = GET_REG(cur_op, 2).o;
-                        REPR(obj)->pos_funcs->at_pos(tc, STABLE(obj), obj,
-                            OBJECT_BODY(obj), GET_REG(cur_op, 4).i64,
-                            &GET_REG(cur_op, 0), MVM_reg_obj);
+                        MVMRegister *out_reg = &GET_REG(cur_op, 0);
+                        MVMObject *out_obj = out_reg->o;
+                        MVMRegister *in_reg = &GET_REG(cur_op, 2);
+                        MVMObject *in_obj = in_reg->o;
+                        
+                        MVMObject *type;
+                        MVMObject *temp_obj;
+                        
+                        MVMArrayREPRData *repr_data = (MVMArrayREPRData *)STABLE(in_obj)->REPR_data;
+
+                        switch (repr_data->slot_type) {
+                            case MVM_ARRAY_OBJ:
+                                REPR(in_obj)->pos_funcs->at_pos(tc, STABLE(in_obj), in_obj,
+                                    OBJECT_BODY(in_obj), GET_REG(cur_op, 4).i64,
+                                    out_reg, MVM_reg_obj);
+                                break;
+                            case MVM_ARRAY_I64:
+                                type = tc->instance->boot_types->BOOTInt;
+                                temp_obj  = REPR(type)->allocate(tc, STABLE(type));
+                            
+                                MVMRegister temp_reg;
+                            
+                                REPR(in_obj)->pos_funcs->at_pos(tc, STABLE(in_obj), in_obj,
+                                    OBJECT_BODY(in_obj), GET_REG(cur_op, 4).i64,
+                                    &temp_reg, MVM_reg_int64);
+                                
+                                MVMROOT(tc, temp_reg, {
+                                    if (REPR(temp_obj)->initialize)
+                                        REPR(temp_obj)->initialize(tc, STABLE(temp_obj), temp_obj, OBJECT_BODY(temp_obj));
+                                    REPR(temp_obj)->box_funcs->set_int(tc, STABLE(temp_obj), temp_obj,
+                                        OBJECT_BODY(temp_obj), temp_reg.i64);
+                                    GET_REG(cur_op, 0).o = temp_obj;
+                                });
+                                break;
+                        }
+
                         cur_op += 6;
                         break;
                     }