Give the `IDWALK_…` enum an explicit name: `LibraryForeachIDFlag`. 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_NOP` as that has the same value
and is of the right type.
One invalid use of `IDWALK_CB_NOP` was detected by this change, and is
replaced by `IDWALK_NOP`.
This change might be incomplete; I gave the enum a name, and then fixed
the compiler errors.
No functional changes.
Pull Request: https://projects.blender.org/blender/blender/pulls/131865
8dd1eb4e8f