Give the `IDWALK_CB_…` enum an explicit name:
`LibraryForeachIDCallbackFlag`. This way the flags are type-safe, and
it's known where values come from. This is much preferred (at least by
me) to just having `int flags`.
Uses of `0` have been replaced with `IDWALK_CB_NOP` as that has the same
value and is of the right type.
One invalid use of `IDWALK_NOP` was detected by this change, and is
replaced by `IDWALK_CB_NOP`.
This change might be incomplete; I gave the enum a name, fixed the
compiler errors, and then also updated assignments like `int cb_flag =
cb_data->cb_flag`. I might have missed some assignments to `int` though.
No functional changes.
Pull Request: https://projects.blender.org/blender/blender/pulls/131865
efd2e762f7