Replace backend$config by backend$inc_config

[myreen]

Currently, we have two compiler configs. The original one:

https://github.com/CakeML/cakeml/blob/8f782f6b8ebd26b0c84d781bc1922f3b66149d7b/compiler/backend/backendScript.sml#L24-L38

And the version adapted for Eval:

https://github.com/CakeML/cakeml/blob/8f782f6b8ebd26b0c84d781bc1922f3b66149d7b/compiler/backend/backendScript.sml#L634-L648

The original is called config and the new version is called inc_config. The only difference between them is that inc_config drops asm_conf from within lab_conf, since it contains function fields in a record type. Function types don't serialise well to text (for Eval) and the cv translator also struggles them.

This issue is about replacing config by inc_config everywhere.

[tanyongkiam]

The labLang configuration should also be replaced and shmem_rec should be replaced by shmem_info_num

[tanyongkiam]

this really ought to be done sooner, so that issues like #1266 cannot happen