pan/bi: Move bi_registers to bi_bundle

Make it a part of the IR itself.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5260>
diff --git a/src/panfrost/bifrost/compiler.h b/src/panfrost/bifrost/compiler.h
index 349aff4..b167b8d 100644
--- a/src/panfrost/bifrost/compiler.h
+++ b/src/panfrost/bifrost/compiler.h
@@ -325,10 +325,12 @@
 };
 
 /* A bi_bundle contains two paired instruction pointers. If a slot is unfilled,
- * leave it NULL; the emitter will fill in a nop.
+ * leave it NULL; the emitter will fill in a nop. Instructions reference
+ * registers via ports which are assigned per bundle.
  */
 
 typedef struct {
+        struct bi_registers regs;
         bi_instruction *fma;
         bi_instruction *add;
 } bi_bundle;