YJIT: Filter & calls from specialized C method codegen

Evident with the crash reported in [Bug #20997], the C replacement
codegen functions aren't authored to handle block arguments (nor
should they because the extra code from the complexity defeats
optimization). Filter sites with VM_CALL_ARGS_BLOCKARG.

bootstraptest/test_yjit.rb

@@ -5347,3 +5347,11 @@ def reverse_even
 
   Swap.new("xy").swap + Swap.new("cat").reverse_odd + Swap.new("abcd").reverse_even
 RUBY
+
+assert_normal_exit %{
+  class Bug20997
+    def foo(&) = self.class.name(&)
+
+    new.foo
+  end
+}

yjit/src/codegen.rs

@@ -6894,11 +6894,12 @@ fn gen_send_cfunc(
     // Increment total cfunc send count
     gen_counter_incr(jit, asm, Counter::num_send_cfunc);
 
-    // Delegate to codegen for C methods if we have it.
+    // Delegate to codegen for C methods if we have it and the callsite is simple enough.
     if kw_arg.is_null() &&
             !kw_splat &&
             flags & VM_CALL_OPT_SEND == 0 &&
             flags & VM_CALL_ARGS_SPLAT == 0 &&
+            flags & VM_CALL_ARGS_BLOCKARG == 0 &&
             (cfunc_argc == -1 || argc == cfunc_argc) {
         let expected_stack_after = asm.ctx.get_stack_size() as i32 - argc;
         if let Some(known_cfunc_codegen) = lookup_cfunc_codegen(unsafe { (*cme).def }) {