nir/lower_subgroups: add extra filter data to options

It might be convenient for filter implementations to have access to
extra information. This will be used, for example, by ir3 to access
compiler features.

Signed-off-by: Job Noorman <jnoorman@igalia.com>
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/31731>

src/compiler/nir/nir.h

@@ -6144,10 +6144,13 @@ bool nir_lower_atomics(nir_shader *shader, nir_instr_filter_cb filter);
 typedef struct nir_lower_subgroups_options {
    /* In addition to the boolean lowering options below, this optional callback
     * will filter instructions for lowering if non-NULL. The data passed will be
-    * this options struct itself.
+    * filter_data.
     */
    nir_instr_filter_cb filter;
 
+   /* Extra data passed to the filter. */
+   const void *filter_data;
+
    /* In case the exact subgroup size is not known, subgroup_size should be
     * set to 0. In that case, the maximum subgroup size will be calculated by
     * ballot_components * ballot_bit_size.