drop-in type check for rb_define_singleton_method

We can check the function pointer passed to
rb_define_singleton_method like how we do so in rb_define_method.
Doing so revealed many arity mismatches.

1 files changed, 1 insertions, 1 deletions

diff --git a/re.c b/re.c
index d5f9a8792e..e61d9bc88c 100644
--- a/re.c
+++ b/re.c
@@ -3998,7 +3998,7 @@ match_setter(VALUE val, ID _x, VALUE *_y)
  */
 
 static VALUE
-rb_reg_s_last_match(int argc, VALUE *argv)
+rb_reg_s_last_match(int argc, VALUE *argv, VALUE _)
 {
     if (rb_check_arity(argc, 0, 1) == 1) {
         VALUE match = rb_backref_get();