pan/bi: Add blend_location to IR for BI_BLEND

To specify which render target is being written.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4097>
diff --git a/src/panfrost/bifrost/compiler.h b/src/panfrost/bifrost/compiler.h
index c63f175..71d1b24 100644
--- a/src/panfrost/bifrost/compiler.h
+++ b/src/panfrost/bifrost/compiler.h
@@ -242,6 +242,9 @@
                 /* For CSEL, the comparison op. BI_COND_ALWAYS doesn't make
                  * sense here but you can always just use a move for that */
                 enum bi_cond csel_cond;
+
+                /* For BLEND -- the location 0-7 */
+                unsigned blend_location;
         };
 } bi_instruction;