Problem: Installing treesitter parser is hard (harder than
climbing to heaven).
Solution: Add optional support for wasm parsers with `wasmtime`.
Notes:
* Needs to be enabled by setting `ENABLE_WASMTIME` for tree-sitter and
Neovim. Build with
`make CMAKE_EXTRA_FLAGS=-DENABLE_WASMTIME=ON
DEPS_CMAKE_FLAGS=-DENABLE_WASMTIME=ON`
* Adds optional Rust (obviously) and C11 dependencies.
* Wasmtime comes with a lot of features that can negatively affect
Neovim performance due to library and symbol table size. Make sure to
build with minimal features and full LTO.
* To reduce re-compilation times, install `sccache` and build with
`RUSTC_WRAPPER=<path/to/sccache> make ...`
Problem: Adding support for modern Nvim features (reflow, OSC 8, full
utf8/emoji support) requires coupling libvterm to Nvim internals
(e.g., utf8proc).
Solution: Vendor libvterm at v0.3.3.
utf8proc contains all the data which is currently in
unicode_tables.generated.h internally, but in quite a different format.
Ideally unicode_tables.generated.h should be removed as well so we rely
solely on utf8proc. We want to avoid a situation where the possibility
of unicode mismatch occurs, e.g a distro using both unicode 12 and
unicode 13.
