radeonsi: deal with ac_nir_translate failures

ac_nir_translate can fail now so forward the translation result to
si_llvm_compile_shader. If it's a failure, it'll print something like:
  radeonsi: can't compile a main shader part
And the shader won't be used.

Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18147>

src/gallium/drivers/radeonsi/si_shader_llvm.c

@@ -1069,7 +1069,8 @@ bool si_llvm_translate_nir(struct si_shader_context *ctx, struct si_shader *shad
       }
    }
 
-   ac_nir_translate(&ctx->ac, &ctx->abi, &ctx->args, nir);
+   if (!ac_nir_translate(&ctx->ac, &ctx->abi, &ctx->args, nir))
+      return false;
 
    switch (sel->stage) {
    case MESA_SHADER_VERTEX:

src/gallium/drivers/radeonsi/si_state_shaders.cpp

@@ -3034,7 +3034,12 @@ static void si_init_shader_selector_async(void *job, void *gdata, int thread_ind
          /* Compile the shader if it hasn't been loaded from the cache. */
          if (!si_compile_shader(sscreen, compiler, shader, debug)) {
             FREE(shader);
-            fprintf(stderr, "radeonsi: can't compile a main shader part\n");
+            fprintf(stderr,
+               "radeonsi: can't compile a main shader part (type: %s, name: %s).\n"
+               "This is probably a driver bug, please report "
+               "it to https://gitlab.freedesktop.org/mesa/mesa/-/issues.\n",
+               gl_shader_stage_name(shader->selector->stage),
+               shader->selector->info.base.name);
             return;
          }