nir: add names to function parameters
SPIR-V has this information. We should try to preserve it.
In this series, we...
- add the new field
- pretty-print it in NIR
- plumb it through vtn
- plumb it through vtn bindgen
There are two immediate wins from this:
- better IDE behaviour with vtn bindgen
- more useful info in nir_print
Edited by Alyssa Rosenzweig