Remove "simple" flag from forwarded ICs

I don't think we should ever consider forwarded IC's to be "simple".
Previously, the "simple" flag would be copied to the derived IC and this
happened to cause struct set / get iseqs to write an invalid CC
fastpath:

  https://github.com/tenderlove/ruby/blob/f45eb3dcb9c7d849064cb802953f37e1cf9f3996/vm_insnhelper.c#L4726-L4729

[Bug #20799]

1 files changed, 1 insertions, 1 deletions

diff --git a/vm_args.c b/vm_args.c
index 0ecdc31a31..28f685d7dd 100644
--- a/vm_args.c
+++ b/vm_args.c
@@ -1177,7 +1177,7 @@ vm_caller_setup_fwd_args(const rb_execution_context_t *ec, rb_control_frame_t *r
 
     *adjusted_ci = VM_CI_ON_STACK(
             site_mid,
-            (caller_flag | (site_flag & (VM_CALL_FCALL | VM_CALL_FORWARDING))),
+            ((caller_flag & ~VM_CALL_ARGS_SIMPLE) | (site_flag & (VM_CALL_FCALL | VM_CALL_FORWARDING))),
             site_argc + caller_argc,
             kw
             );