Hoist out auxiliary values in optional-typed arguments (pytorch#123613)

This fixes pytorch#123176, and partially addresses pytorch#121814 too. pytorch#123176 uses an
optional device arg while pytorch#121814 uses an optional list arg.

For optional arguments that have auxiliary info -- specifically, tuples
/ lists with their length parameter, and device types with their device
index -- we need to hoist out the extra argument. E.g. when passing a
device with ID 1, we want to emit

```
auto var_0 = cached_torch_device_type_cpu;
aoti_torch_foo(..., &var_0, 1);
```

instead of the (syntactically incorrect)

```
auto var_0 = cached_torch_device_type_cpu,1;
aoti_torch_foo(..., &var_0);
```

Pull Request resolved: pytorch#123613
Approved by: https://github.com/desertfire

Author: int3

test/inductor/test_cpu_cpp_wrapper.py

@@ -88,7 +88,6 @@ class DynamicShapesCppWrapperCpuTests(InductorTestCase):
         "test_qlinear_cpu",
         "test_qlinear_dequant_promotion_cpu",
         "test_qlinear_relu_cpu",
-        "test_randn_with_dtype_and_device_cpu",
         "test_scatter5_cpu",
         "test_scatter6_cpu",
         "test_tensor2_cpu",

torch/_inductor/codegen/cpp_wrapper_cpu.py

@@ -1403,7 +1403,7 @@ def generate_inf_and_nan_checker(self, nodes):
     def codegen_device(self, device):
         if config.abi_compatible:
             self.used_cached_devices.add(device.type)
-            return f"cached_torch_device_type_{device.type},{device.index if device.index else 0}"
+            return f"cached_torch_device_type_{device.type}, {device.index if device.index else 0}"
         else:
             from .cpp import DEVICE_TO_ATEN
 
@@ -2093,8 +2093,22 @@ def val_to_cpp_arg_str(self, type_, val) -> str:
                 return "0"  # nullptr is not available in C
             if not isinstance(type_.getElementType(), torch.TensorType):
                 var_name = f"var_{next(self.arg_var_id)}"
-                self.writeline(f"auto {var_name} = {self.val_to_arg_str(val)};")
-                return f"&{var_name}"
+                if isinstance(
+                    type_.getElementType(),
+                    (torch.ListType, torch.TupleType, torch.DeviceObjType),
+                ):
+                    arg_str = self.val_to_arg_str(val)
+                    if val is None:
+                        return "{arg_str}, 0"
+                    else:
+                        # For datatypes with auxiliary info, we need to hoist out the extra arguments.
+                        # NOTE: This only works if there is one additional argument, though it can easily be generalized.
+                        main_value, aux = arg_str.rsplit(", ")
+                        self.writeline(f"auto {var_name} = {main_value};")
+                        return f"&{var_name}, {aux}"
+                else:
+                    self.writeline(f"auto {var_name} = {self.val_to_arg_str(val)};")
+                    return f"&{var_name}"
             elif config.c_shim_version == "2":
                 # Similar to other data type, use pointer to denote optional tensor arg in v2 C shim
                 base_handle = self.val_to_arg_str(val)

torch/csrc/inductor/aoti_torch/utils.h

@@ -141,7 +141,7 @@ inline std::array<bool, N> pointer_to_list(const int32_t* ptr) {
   return result;
 }
 
-// utility functions to convert a pointer to a list of optional values
+// Utility function to convert a pointer to an optional list of values
 template <class T, class U>
 inline c10::optional<c10::ArrayRef<T>> pointer_to_optional_list(
     U** ptr,