YJIT: Pass nil to anonymous kwrest when empty (#9972)

This is the same optimization as e4272fd29 ("Avoid allocation when
passing no keywords to anonymous kwrest methods") but for YJIT. For
anonymous kwrest parameters, nil is just as good as an empty hash.

On the usage side, update `splatkw` to handle `nil` with a leaner path.

1 files changed, 6 insertions, 0 deletions

diff --git a/yjit.c b/yjit.c
index 4e9fed35ae..207974073b 100644
--- a/yjit.c
+++ b/yjit.c
@@ -660,6 +660,12 @@ rb_get_iseq_flags_has_kwrest(const rb_iseq_t *iseq)
 }
 
 bool
+rb_get_iseq_flags_anon_kwrest(const rb_iseq_t *iseq)
+{
+    return iseq->body->param.flags.anon_kwrest;
+}
+
+bool
 rb_get_iseq_flags_has_rest(const rb_iseq_t *iseq)
 {
     return iseq->body->param.flags.has_rest;