nak: Make ShaderBin a public struct

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30275>

src/nouveau/compiler/nak/api.rs

@@ -204,7 +204,7 @@ pub extern "C" fn nak_nir_options(
 }
 
 #[repr(C)]
-struct ShaderBin {
+pub struct ShaderBin {
     bin: nak_shader_bin,
     code: Vec<u32>,
     asm: CString,
@@ -337,6 +337,14 @@ impl ShaderBin {
     }
 }
 
+impl std::ops::Deref for ShaderBin {
+    type Target = nak_shader_bin;
+
+    fn deref(&self) -> &nak_shader_bin {
+        &self.bin
+    }
+}
+
 #[no_mangle]
 pub extern "C" fn nak_shader_bin_destroy(bin: *mut nak_shader_bin) {
     unsafe {