nir: update nir->num_inputs, num_outputs in nir_recompute_io_bases()

Since nir_recompute_io_bases is going to be used instead of
nir_assign_io_var_locations, we need to update num_inputs, num_outputs.

Reviewed-by: Qiang Yu <yuq825@gmail.com>
Reviewed-by: Timur Kristóf <timur.kristof@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/21861>

src/compiler/nir/nir_lower_mediump.c

@@ -130,6 +130,11 @@ nir_recompute_io_bases(nir_shader *nir, nir_variable_mode modes)
       nir_metadata_preserve(impl, nir_metadata_all);
    }
 
+   if (modes & nir_var_shader_in)
+      nir->num_inputs = BITSET_COUNT(inputs);
+   if (modes & nir_var_shader_out)
+      nir->num_outputs = BITSET_COUNT(outputs);
+
    return changed;
 }