pan/bi: Recoalesce tied operands after spilling

Otherwise we can fail to allocate tied operands if we spill the tied operand.
Seen in shaders/android/com.miHoYo.GenshinImpact/16.shader_test with a
particularly bad scheduling causing excessive spilling.

No shader-db changes.

Fixes: bc17288697 ("pan/bi: Lower split/collect before RA")
Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16378>

src/panfrost/bifrost/bi_ra.c

@@ -818,6 +818,11 @@ bi_register_allocate(bi_context *ctx)
                         spill_count += bi_spill_register(ctx,
                                         bi_node_to_index(spill_node, bi_max_temp(ctx)),
                                         spill_count);
+
+                        /* In case the spill affected an instruction with tied
+                         * operands, we need to fix up.
+                         */
+                        bi_coalesce_tied(ctx);
                 }
         }