functoria: Quote Runtime_arg.call

[Julow]

Fixes codes that use an arg call as an argument to a function:

code ~pos:__POS__ "f ~arg:%a"
  Runtime_arg.call my_arg

[samoht]

Thanks! Do you have a use-case for this? Devices are not supposed to call function (the initial goal was that only functoria would use this)

[Julow]

I found this problem when updating this to mirage 4.5: https://github.com/robur-coop/caldav/blob/main/mirage/config.ml#L91

Key.serialize_call prints something that can be on the RHS of a label argument (either parenthesized or an identifier) but Runtime_arg.call do not and I hoped to swap one for the other.

[samoht]

With the new API the argument name is passed as the last parameters of the call to connect. You can then just use it directly, you don't need to serialize it yourself.

We should probably remove that function from the public API to avoid people doing this :-)

[Julow]

This is indeed not needed in robur-coop/caldav#36, thanks!

Runtime_arg.call is still needed within mirage, so I think quoting doesn't hurt.