anv: Pre-compute push ranges for graphics pipelines

It turns off that emitting push constants is one of the hottest paths in
the driver and ANY work we do there costs us.  By pre-computing things a
bit ahead of time, we shave 5% off the runtime of a CPU-limited example
running with the Dawn WebGPU implementation.

Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>

src/intel/vulkan/anv_nir.h

@@ -59,6 +59,10 @@ void anv_nir_apply_pipeline_layout(const struct anv_physical_device *pdevice,
                                    struct brw_stage_prog_data *prog_data,
                                    struct anv_pipeline_bind_map *map);
 
+void anv_compute_push_layout(const struct anv_physical_device *pdevice,
+                             struct brw_stage_prog_data *prog_data,
+                             struct anv_pipeline_bind_map *map);
+
 bool anv_nir_add_base_work_group_id(nir_shader *shader,
                                     struct brw_cs_prog_data *prog_data);