nak: Unconditionally call lower_io_to_temporaries in preprocess_nir

We're calling it for fragment shaders and NVK is calling it for
eerything before invoking NAK so we may as well call it unconditionally
in NAK and skip calling it in NVK.

Reviewed-by: Lorenzo Rossi <snowycoder@gmail.com>
Acked-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Mel Henning <mhenning@darkrefraction.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30403>

src/nouveau/compiler/nak_nir.c

@@ -299,10 +299,9 @@ nak_preprocess_nir(nir_shader *nir, const struct nak_compiler *nak)
 
    nir_validate_ssa_dominance(nir, "before nak_preprocess_nir");
 
-   if (nir->info.stage == MESA_SHADER_FRAGMENT) {
-      nir_lower_io_to_temporaries(nir, nir_shader_get_entrypoint(nir),
-                                  true /* outputs */, false /* inputs */);
-   }
+   OPT(nir, nir_lower_io_to_temporaries,
+       nir_shader_get_entrypoint(nir),
+       true /* outputs */, false /* inputs */);
 
    const nir_lower_tex_options tex_options = {
       .lower_txd_3d = true,

src/nouveau/vulkan/nvk_shader.c

@@ -136,9 +136,6 @@ nvk_preprocess_nir(struct vk_physical_device *vk_pdev,
    const struct nvk_physical_device *pdev =
       container_of(vk_pdev, struct nvk_physical_device, vk);
 
-   NIR_PASS(_, nir, nir_lower_io_to_temporaries,
-              nir_shader_get_entrypoint(nir), true, false);
-
    nak_preprocess_nir(nir, pdev->nak);
 }