Support `:stdin` for `ob-C` for org-mode

org-babel-C-execute-filter-args.el

(advice-add 'org-babel-C-execute
            :filter-args
            (defun sloth/org-babel-C-execute/filter-args (args)
              (when-let* ((params (cadr args))
                          (stdin (cdr (assoc :stdin params)))
                          (res (org-babel-ref-resolve stdin))
                          (stdin (org-babel-temp-file "c-stdin-")))
		(with-temp-file stdin (insert res))
                (let* ((cmdline (assoc :cmdline params))
                       (cmdline-val (or (cdr cmdline) "")))
                  (when cmdline (setq params (delq cmdline params)))
                  (setq params
                        (cons (cons :cmdline (concat cmdline-val " <" stdin))
                              params))
                  (setf (cadr args) params)))
              args))