nir/dead_variables: Configurably work with any variable mode

The old version of the pass only worked on globals and locals and always
left inputs, outputs, uniforms, etc. alone.

Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>

src/compiler/nir/nir.h

@@ -2205,7 +2205,7 @@ nir_src *nir_get_io_vertex_index_src(nir_intrinsic_instr *instr);
 
 void nir_lower_vars_to_ssa(nir_shader *shader);
 
-bool nir_remove_dead_variables(nir_shader *shader);
+bool nir_remove_dead_variables(nir_shader *shader, nir_variable_mode modes);
 
 void nir_move_vec_src_uses_to_dest(nir_shader *shader);
 bool nir_lower_vec_to_movs(nir_shader *shader);