vm_insnhelper.c: use update argc

* vm_insnhelper.c (vm_invoke_block): use ci->argc updated by
  CALLER_SETUP_ARG().  [Bug #11451]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@51655 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

vm_insnhelper.c

@@ -2336,9 +2336,9 @@ vm_invoke_block(rb_thread_t *th, rb_control_frame_t *reg_cfp, rb_call_info_t *ci
     }
     else {
 	VALUE val;
-	int argc = ci->argc;
+	int argc;
 	CALLER_SETUP_ARG(th->cfp, ci);
-
+	argc = ci->argc;
 	val = vm_yield_with_cfunc(th, block, block->self, argc, STACK_ADDR_FROM_TOP(argc), 0);
 	POPN(argc); /* TODO: should put before C/yield? */
 	return val;