Remove the `ucd` dependency which has not been updated in 8 years. In
addition, replace it with a generated UnicodeBlock enum which reflects
the modern Unicode standard. This is generated via a Python script which
is included in the repository. The generation is not part of the build
process, because the Unicode database is hosted on the web and it does
not change the frequently.
This is done instead of bringing in the more up-to-date `unicode_blocks`
dependency. `unicode_blocks` defines each block as constant, which means
that they cannot be used in match statements -- which we do in Servo.
Co-authored-by: Lauryn Menard <lauryn.menard@gmail.com>
For a long time, `gfx_traits` has held a lot of things unrelated to graphics
and also unrelated to the `gfx` crate (which is mostly about fonts).
This is a cleanup which does a few things:
1. Move non `gfx` crate things out of `gfx_traits`. This is important in
order to prevent dependency cycles with a different integration between
layout, script, and fonts.
2. Rename the `msg` crate to `base`. It didn't really contain anything
to do with messages and instead mostly holds ids, which are used
across many different crates in Servo. This new crate will hold the
*rare* data types that are widely used.
Details:
- All BackgroundHangMonitor-related things from base to a new
`background_hang_monitor_api` crate.
- Moved `TraversalDirection` to `script_traits`
- Moved `Epoch`-related things from `gfx_traits` to `base`.
- Moved `PrintTree` to base. This should be widely useful in Servo.
- Moved `WebrenderApi` from `base` to `webrender_traits` and renamed it
to `WebRenderFontApi`.
