stack_to_lab in compilationLib should take all configs as arguments

[oskarabrahamsson]

Using compilationLib with custom configs doesn't work because the library is hard-coded to use only the standard configs, see here: https://github.com/CakeML/cakeml/blob/master/compiler/compilationLib.sml#L165-L184.

Here are some things that might differ between configs:

• the foo_name_defs
• the foo_encode_compsets
• the foo_backend_config_defs