nir: add a nir_remove_non_entrypoints helper

This code just got duplicated a lot. There is still more, but the
remaining instances do a bit more than just removing other functions.

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16348>

src/compiler/nir/nir.c

@@ -3516,3 +3516,12 @@ void nir_remove_sysval_output(nir_intrinsic_instr *intr)
       nir_instr_remove(&intr->instr);
    }
 }
+
+void nir_remove_non_entrypoints(nir_shader *nir)
+{
+   foreach_list_typed_safe(nir_function, func, node, &nir->functions) {
+      if (!func->is_entrypoint)
+         exec_node_remove(&func->node);
+   }
+   assert(exec_list_length(&nir->functions) == 1);
+}

src/compiler/nir/nir.h

@@ -3669,6 +3669,8 @@ nir_shader_get_entrypoint(const nir_shader *shader)
    return func->impl;
 }
 
+void nir_remove_non_entrypoints(nir_shader *shader);
+
 nir_shader *nir_shader_create(void *mem_ctx,
                               gl_shader_stage stage,
                               const nir_shader_compiler_options *options,