pan/bi: Add builder initialization helper

When going out of NIR, it's useful to start inserting instructions at
the end of the current block.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8135>

src/panfrost/bifrost/bifrost_compile.c

@@ -36,6 +36,7 @@
 #include "compiler.h"
 #include "bi_quirks.h"
 #include "bi_print.h"
+#include "bi_builder.h"
 
 static const struct debug_named_value debug_options[] = {
         {"msgs",      BIFROST_DBG_MSGS,		"Print debug messages"},
@@ -57,6 +58,15 @@ int bifrost_debug = 0;
 			fprintf(stderr, "%s:%d: "fmt, \
 				__FUNCTION__, __LINE__, ##__VA_ARGS__); } while (0)
 
+static inline bi_builder
+bi_init_builder(bi_context *ctx)
+{
+        return (bi_builder) {
+                .shader = ctx,
+                .cursor = bi_after_block(ctx->current_block)
+        };
+}
+
 static bi_block *emit_cf_list(bi_context *ctx, struct exec_list *list);
 static bi_instruction *bi_emit_branch(bi_context *ctx);