kraid: Plumb through Model::encode_shader()

Of course, we can't actually encode anything yet but this gives us the
model hook and deals with the util_dynarray so that everything inside
the model hook is safe code.

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/41841>

src/panfrost/compiler/kraid/compile.rs

@@ -46,11 +46,23 @@ fn dump_shader(s: &Shader, suffix: &str) {
     eprintln!("Kraid shader {suffix}:{out}");
 }
 
+fn dynarray_append_vec<T: Copy>(buf: &mut util_dynarray, vec: Vec<T>) {
+    unsafe {
+        let p = util_dynarray_grow_bytes(
+            buf,
+            vec.len().try_into().unwrap(),
+            std::mem::size_of::<T>(),
+        );
+        assert!(!p.is_null(), "util_dynarray_grow_bytes() failed");
+        std::ptr::copy_nonoverlapping(vec.as_ptr(), p as *mut T, vec.len());
+    }
+}
+
 #[no_mangle]
 pub extern "C" fn kraid_compile_nir(
     nir: &mut nir_shader,
     inputs: &pan_compile_inputs,
-    _binary: &mut util_dynarray,
+    binary: &mut util_dynarray,
     _info: &mut pan_shader_info,
 ) {
     let model = model_for_gpu_id(inputs.gpu_id).unwrap();
@@ -65,5 +77,6 @@ pub extern "C" fn kraid_compile_nir(
     dump_shader(&s, "after register assignment");
     s.validate();
 
-    todo!("Compile to binaries");
+    let bin = model.encode_shader(&s);
+    dynarray_append_vec(binary, bin);
 }

src/panfrost/compiler/kraid/model.rs

@@ -1,10 +1,13 @@
 // Copyright © 2026 Collabora, Ltd.
 // SPDX-License-Identifier: MIT
 
+use crate::ir::*;
 use kraid_bindings::*;
 
 pub trait Model {
     fn arch(&self) -> u8;
+
+    fn encode_shader(&self, s: &Shader<'_>) -> Vec<u32>;
 }
 
 struct ValhallModel {
@@ -15,6 +18,10 @@ impl Model for ValhallModel {
     fn arch(&self) -> u8 {
         self.arch
     }
+
+    fn encode_shader(&self, _s: &Shader<'_>) -> Vec<u32> {
+        todo!("Implement Valhall shader encoding");
+    }
 }
 
 pub fn model_for_gpu_id(gpu_id: u64) -> Result<Box<dyn Model>, &'static str> {