The Fast dictionary-table projection was populated before the Rust
orchestrator ran its window-update and match-state publication callbacks.
That left base and nextToUpdate pointing at the initial sentinel for MT
prefix jobs, which caused ZSTD_rust_fillHashTable to dereference an invalid
range. Project pointers to the live match-state fields so Rust reads the
same values the former C adapter would have read at the Fast branch.
Test Plan:
- git diff --check
- ulimit -v 41943040; CARGO_BUILD_JOBS=1 cargo check --manifest-path rust/Cargo.toml --tests
- ulimit -v 41943040; make -j1
- capped 4 MiB -T0 compress/decompress round trip with cmp